The Behavior Analyst 1987, 10, 47-65 No. 1 (Spring)

Quantitative Order in B. F. Skinner's EarlyResearch Program, 1928-1931

S. R. ColemanCleveland State University

The purpose ofthis article is to provide a coherent story ofSkinner's graduate-school (1928-193 1) researchprojects, adding to Skinner's own accounts a different emphasis and a number of interesting details. Thestory is guided by the proposal that a search for quantitative order was the "unifying force" amid thevariety of apparatus changes and shifts of research topic in Skinner's early development as a researcher.Archival laboratory-research records from several apparatuses which Skinner constructed between 1928and 1931 (1) indicate that his research program was more complicated than he has implied; (2) showthat he worked on three interdependent lines of investigation simultaneously; (3) suggest that change orabandonment ofan apparatus or a project was markedly affected by his success (and failure) in his primaryobjective, which was to find quantitative orderliness in measured behavior. Frequent apparatus changein the period of 1928 to 1930 ceased when he obtained quantitative orderliness in the panel-press andlever-box preparations. In the examination of archival records, questions about the enterprise of bio-graphical understanding are considered.Key words: Skinner, B. F., history of psychology, quantification, cumulative record, apparatus, meth-

odology

It is argued that research would be aimless anddisorganized without a theory to guide it. The viewis supported by psychological texts that. . . describethinking as necessarily involving stages of hypoth-esis, deduction, experimental test, and confirma-tion. But this is not the way most scientists actuallywork. (Skinner, 1950, pp. 194-195, emphasis added)

I never attacked a problem by constructing a Hy-pothesis. I never deduced Theorems or submittedthem to Experimental Check. So far as I can see, Ihad no preconceived Model of behavior .... Ofcourse, I was working on a basic Assumption-thatthere was order in behavior if I could only discoverit. (Skinner, 1956a, p. 227)When we try to make sense of an ex-

tended series of happenings by using therough-and-ready conceptual system ofdaily-life explanation, we engage in sev-

Reprints are available from S. R. Coleman, De-partment of Psychology, Cleveland State Univer-sity, Cleveland, Ohio 44115. This research was sup-ported through the Expense Grant Program of theCollege ofGraduate Studies at Cleveland State Uni-versity. A preliminary version of this paper waspresented at the annual meeting of the Cheiron So-ciety, June 13, 1986, at the University of Guelph,Ontario.

Archival figures, data, and notes are used withpermission ofthe Harvard University Archives andof B. F. Skinner. I wish to acknowledge courteousassistance from B. F. Skinner, Clark Elliott, andCuthbert Daniel; good suggestions by this journal'seditor and reviewers; and helpful conversation withJack Seigel, Phil Emerson, Louis Milic, and BrianClearmountain.

eral different activities. We try to rec-ognize how disparate items are related asparts of the same development, or we tryto see how their similarities (qua parts)are greater, or at least more important,than their more readily noticed differ-ences. Moreover, we think of the devel-opment as a unitary thing which is tend-ing toward a goal, and we evaluate thedistinguishable parts as contributing toor hindering progress toward that goal.Occasionally, we make informed guessesat the "causes" of particular parts of thedevelopment, especially ofthose that arehindrances to progress; but, when it isdifficult to ascertain the cause ofan event,we try to see how it fits into the overallpattern of surrounding events or whatcontribution it makes to reaching the goalofthe development. The study of histor-ical developments of all sorts, includingpersonal history, makes extensive use ofthis pattern-seeking strategy for under-standing, since experimentation and oth-er sources of knowledge based on ma-nipulation are usually unavailable.

In looking for a pattern in personal de-velopment, we typically call attention tosomething that we see as central (e.g., anenduring personality trait). We may thinkof the trait as the principal causal factorbehind various observable activities of

47

48 S. R. COLEMAN

the individual. Or we may imagine thata unifying process (e.g., a personal theme)is more powerful than the "forces" re-sponsible for diverse and peripheral phe-nomena. Continuing the spatial meta-phor, we could call the latter forces"centrifugal," since they tend away fromthe center and produce diversity and in-consistency that make patterns hard todiscern. It is possible, though, to assumethat centrifugal forces are very signifi-cant. There is a novelistic tradition, thenovel of manners and circumstance, inwhich detailed description of social life,conventions, and their binding effect onmain characters is the primary stuff ofthe novel. Examples include the novelsof Jane Austen and Honore de Balzac,Dickens's Hard Times, Thackeray's Van-ity Fair, Sterne's Tristram Shandy, manyof Trollope's works, and much of theAmerican twentieth-century Realisticnovel (Upton Sinclair, John Dos Passos,Sinclair Lewis, etc.). While it is true thatthe principal characters in these novelsdo provide narrative unification, it is clearthat in the tug of war between unity anddiversity a considerable latitude of em-phasis is permissible. Accordingly, inmaking sense of Skinner's early devel-opment as a laboratory researcher, itwould be legitimate to emphasize eitherunifying factors or centrifugal factors,even though daily-life explanation mightincline one more to search for unity.Unity and coherence are not readily

apparent, however, when one examinesB. F. Skinner's personal development asreported in his autobiographies (Skinner,1976, 1979, 1983) and compares it withthe lives ofindividuals who claim to havebeen dominated by a small number ofrelated and enduring concerns, for ex-ample, Carl Jung (Jung, 1961). One mighteven be persuaded that the search for co-herence is an illusory pursuit after read-ing Skinner's pronouncements on per-sonal identity (e.g., Skinner, 1953, pp.284-288; 1974, pp. 164-167, 247), es-pecially if one suspects such pronounce-ments are at least partially autobiograph-ical (cf. Skinner, 1976, p. 255). Of course,difficulty in finding one or more unifying

themes in Skinner's autobiographicalwritings could merely be a consequenceof his lifelong preference for a descrip-tive, circumstantial writing style (Cole-man, 1985), combined with a hard-head-ed reluctance to hypostatize unifyingforces. Skinner's literary descriptivismleaves the reader with a manifold of par-ticulars, in which diversity is the domi-nant impression. While this state of af-fairs might conceivably stem from merewillfulness as an autobiographer, "thefacts" ofSkinner's life usually support animpression ofdiversity. For example, be-tween 1928, when he enrolled for grad-uate study at Harvard, and 1931, whenhe received the doctorate, Skinner con-structed eight or nine different appara-tuses to carry out a variety of laboratoryinvestigations of animal behavior. Suchdiversity in his research projects of thatperiod justifies attention to circum-stance, happenstance, and other centrif-ugal factors. In describing that period,Skinner's own "Case History in ScientificMethod" (Skinner, 1956a), therefore,placed appropriate emphasis on the im-portance of luck, accident, simple curi-osity, and even laziness, in his scientificdevelopment. Though he argued that suchfactors were very important in his owndevelopment, they had been given vir-tually no recognition in the formalisticand theory-conscious logical-positivistphilosophy of science of that time. 1

In dismissing the alleged importanceoftheories-in the specific sense of "the-

' It is useful and consistent with Skinner's ownpronouncements (e.g., Skinner, 1957, pp. 453-456)to regard his construction of a case history as be-havior involved in a contingency: His emphasis oncircumstance in his own conduct as a scientist(Skinner, 1956a) served the function ofquestioninga philosophical picture ofthe behavior of scientists(e.g., Skinner, 1956a, pp. 221-222), a function whichis understandable enough in the B. F. Skinner ofthe early 1950s (e.g., Skinner, 1950). Of course, anemphasis on centrifugal factors is also simply con-sistent with his highly descriptive practices of thesame period (e.g., Ferster & Skinner, 1957), apartfrom any plan to take exception to a philosophy ofscience that was widely endorsed by his contem-poraries. We will not try to decide in favor ofeitherpossibility.

SKINNER'S QUANTIFICATION 49

ory" described in "Are Theories ofLearning Necessary?" (Skinner, 1950, p.193)-Skinner (1956a) took the searchfor order more or less for granted, as isshown in the second quote which openedthis article. Skinner's quarrel was withthe alleged necessity of behavior theory,not with fundamental assumptions suchas the lawfulness of nature. In discount-ing the necessity of theory in behavioralresearch, it was perhaps inevitable thathe would emphasize centrifugal forces inhis development, since, in relation to the-ory, they lie at the opposite end of thecentral-peripheral contrast. It is true thatin his autobiographical statements, he hasacknowledged the importance of suchfundamental assumptions as the idea thatbehavior is quantitatively orderly andthat the scientist's task is to demonstratesuch order (Skinner, 1956a, pp. 223,224,227; 1979, pp. 59-60, 67-68, 99-100).Nonetheless, since he has devoted morespace to the description of circumstance,the drift ofhis autobiographical accountsis decidedly centrifugal. In his descrip-tions of his own scientific conduct (e.g.,Skinner, 1956a), this feature, or its pre-sumed consequence of "aimless and dis-organized" research-see the first quoteabove-has bothered various writers,prompting some to criticism of his re-search style (e.g., Bixenstine, 1964) andothers to defense (Sidman, 1960). An ob-jective of the present article is to makemore apparent the importance of Skin-ner's search for quantitative order as aunifying factor in his early research pro-gram.

MATERIALS AND METHODSkinner saved an assortment ofrecords

from the research projects of his gradu-ate-student period, and gave these ma-terials to the Harvard University Ar-chives in early 1983. They contain muchof the information that Skinner used inhis own published accounts of his grad-uate-student development as a scientist(Skinner, 1956a, 1967, 1979). Of course,they also include records and notes thatSkinner did not include in his accounts.

The present paper was based primarilyon a study of these materials,2 thoughSkinner's autobiographical writings andhis published research of the 1930s werealso consulted. Prof. Skinner aided in de-ciphering a few records that were difficultto understand, and he responded toquestions about all the records, during aten-day period in 1985, in subsequentcorrespondence, and in remarks on anearlier draft of this paper.The present paper adds to Skinner's

(1979) own account enough additionaldetails for a separate story, and it makesmore explicit than does his "Case His-tory" (Skinner, 1956a) that his early pro-gram of research was much affected bysuccesses and failures in his exploratoryquest for quantitative behavioral regu-larity. In the narrative, questions andconsiderations regarding biographicalunderstanding are raised.

BACKGROUND SKETCHA history of the idea that nature ex-

hibits quantitatively expressible orderli-ness would be distracting, even if it werewithin our capacity. That idea and itssuccessful demonstration go back intoancient science but also were prominentfeatures of the Scientific Revolution ofthe seventeenth century (e.g., Hall, 1954/1956, pp. 224-234; 1963/1981), whichfirst affected the physics and astronomyof that period. Large-scale efforts atquantification in the life sciences (includ-ing physiology) had to await the secondhalfofthe nineteenth century. W. J. Cro-zier, Skinner's graduate-school mentorand dissertation supervisor in Harvard'sDepartment of Physiology, was a cham-pion of quantitative physiological re-search. Because none of the other figures

2 These materials are cataloged in the HarvardUniversity Archives as: Burrhus Frederic SKIN-NER, Laboratory Research Records, 1929-1940,Shelf Number HUG (B) - S485.45. The materialsare in 15 folders, roughly chronologically arrangedand preserving the order in which Prof. Skinnerarranged the materials for accession by the Ar-chives. References to these materials in the presentarticle will include only the Folder number.

50 S. R. COLEMAN

who were important sources of ideas orinspiration for Skinner-such as Watson,Pavlov, Bertrand Russell, H. G. Wells,Sherrington, and Magnus (Skinner, 1976,1979) -were predominantly quantitativein their research methods or objectives,we must assume that Crozier was theprincipal source for the quantitative em-phasis.

Since Skinner's quantitative back-ground was not particularly strong (e.g.,Skinner, 1979, p. 67), there is no obviousaffinity between Crozier's quantitativescientific approach and whatever lean-ings Skinner may have had in that direc-tion. The affinity ofthese two people wasprobably in other issues and dimensions,with quantification of lesser significance.Skinner lacked the quantitative back-ground to become a Crozier disciple, andin addition he had no wish to be one (B.F. Skinner, personal communication, July9, 1985). Nevertheless, Skinner's scien-tific strategy as a graduate-student re-searcher was to assume that orderliness,of at least a simple quantitative sort, ex-isted in the behavior ofthe freely movingorganism, and to seek to demonstrate thisin his various preparations. To make acoherent story out of the available ar-chival records is the task ofthe remainderof this paper.

COURSEWORK ORIGINSSkinner's first two behavioral projects

were undertaken as course requirements.His first published research was carriedout in collaboration with T. C. Barnes forHarvard's Physiology 20a course (titled"Dynamics of Vital Phenomena") whichSkinner took in the spring of 1929.3 Theproject employed ants, and the behaviorof interest was their locomotion upwardon a slanted surface (negative geotro-pism). The degree of slant of the surfacecould be made to vary as the independentvariable, and the angle of straight-linesections of the ant's path along the sur-

I We acknowledge the assistance ofDr. MargaretLaw, Registrar of Harvard University, who madeavailable a transcript of Skinner's courses, fromwhich the course titles and numbers are taken.

face served as the dependent variable.During the spring and summer, he andBarnes worked together in the project'sexecution, analysis, and write-up. Skin-ner's autobiography contains an amusingdescription of the writing process (Skin-ner, 1979, p. 19).

In the spring of 1929, Skinner also tooka research course (Psychology 20c) su-pervised by Walter Hunter, visiting fromClark University. Skinner and DwightChapman collaborated on a project in-volving insightful learning in squirrels, atopic that Skinner said was prompted bythe arrangements for studying problem-solving in apes which Kohler (1925) haddescribed in The Mentality ofApes (B. F.Skinner, personal communication, Au-gust 18, 1986; Skinner, 1979, pp. 30-31).The project was probably supervised byWalter Hunter, but got no publishableresults (Skinner, 1979, p. 30). Skinnereventually provided his squirrels a run-ning wheel, apparently for purpose ofex-ercise and, at least initially, without plansto obtain behavioral data from that ap-paratus (Skinner, 1979, pp. 77-78).

LOCOMOTION RESEARCHSkinner's earliest independently con-

ducted research concerned locomotion(Skinner, 1979, pp. 32-34). He devisedan apparatus he called the Parthenon(Skinner, 1956a, Fig. 1), a tunnel into oneend of which a rat could be introducedfrom Skinner's silent-release carrying box,and out the other end of which the ratwould emerge and hesitantly start to de-scend a couple of steps until Skinner pre-sented a calibrated click which (so hethought at the time) inhibited the reflexesof progression (Magnus, 1924) and elic-ited withdrawal back into the tunnel(Skinner, 1956a, p. 223 and Fig. 1). Skin-ner manually recorded the progress,withdrawal, and re-emergence of the ratby moving a pencil across chart paperdriven at a known speed by a motor (B.F. Skinner, personal communication,August 18, 1986). His equipment per-mitted him to measure what he took tobe a period of prepotency of the click-elicited withdrawal reflexes over the re-

SKINNER'S QUANTIFICATION 51

flexes of progression. That period couldbe measured as a response latency: thetime interval between the rat's with-drawal into the tunnel and its subsequentcomplete re-emergence, at which pointthe click was sounded again. Survivingrecords from the Parthenon work arepoorly labeled, and it was impossible-even with Professor Skinner's aid-to de-temine what was the meaning ofsome ofthe numerals that he had written manyyears ago on the chart paper. The recordsdo not explicitly tell why he abandonedthe Parthenon, ofcourse, but had he plot-ted the data ofthe most easily decipheredrecords (Folder 1), he would have foundthe results displayed in Figure 1.The figure shows that the duration of

withdrawal decreased with repeated pre-sentations of the click: that is, the figuredepicts "adaptation," as he called it, orhabituation of withdrawal. Though ha-bituation is suggested by the course ofthe function, large variability is probablythe more noticeable feature of Figure 1.Elsewhere we have suggested that Skin-ner was philosophically concerned to"conquer" variability and to defend de-terminism (Coleman, 1984, pp. 474 475,479-483). The most direct strategy forreducing variability is to change or re-place unsatisfactory apparatus. Since hewas already acquainted with standardphysiological-laboratory apparatus, it isunlikely that Skinner was attached to hisown crude manual-recording procedures.We suggest that these -and, of course,those described by Skinner (1956a) -arethe prototypical circumstances underwhich Skinner made apparatus changesat this stage of his career.Though Skinner had abandoned the

Parthenon, he continued to study loco-motion and posture in several other de-vices. In the summer of 1929, he plannedobservational studies of posture and lo-comotor activity in very young rats. Ac-cording to surviving notes, which Skin-ner later dated to the summer of 1929,his plan was to photograph or draw dif-ferent postures that resulted from beinglifted up by the tail with more or lesssupport of the torso; and to determinehow additional support-for example,

20

10

Be. 5

5 10

Ordinal Number of Presentations of Click (?)Figure 1. Habituation of withdrawal in Skinner'sParthenon research. Duration of withdrawal as afunction of repeated presentations of a calibratedsound. Figure drawn from values obtained fromraw-data record. Note. Question-mark indicates thatthe archival records were not explicitly labeled withtrial numbers, necessitating guesswork in creatingthis figure.

support ofthe forelimbs- altered the po-sition ofthe head and tail, how it affectedthe amount of body tremor, and how itaffected the various flexion and extensionreflexes which could be elicited (uncata-loged material in Accession 9710, Har-'vard University Archives). The influenceof Magnus (1924) is certainly noticeablein this surviving research plan, but thearchival collection includes no resultsfrom the project, which was probablynever carried out (B. F. Skinner, personalcommunication, August 18, 1986). It isreasonable to conjecture that the absenceof a measurement procedure or device,thus precluding quantitative results, wasthe Achilles' heel ofthis summer project.According to his later reconstruction

(Skinner, 1956a, pp. 223-224), Skinnerabandoned the possibilities of drawingand photography in favor of a mechan-ical recording device, with Skinner re-cording the force with which baby ratsthrust against a horizontal surface whenthe tail is firmly held (Skinner, 1956a,Fig. 2; 1979, pp. 36-37). He did not men-tion any processes that he actually in-vestigated, but since each archival recordis marked with an indication ofthe room

52 S. R. COLEMAN

NOISE

A \ NoT RUN

t ItALTALEANN& fAT ftSIAMEAOO L'bIRUNNING'rFoor RN#Figure 2. Drawing of a section of kymographicrecord from Skinner's torsion-wire runway. Adownward pen deflection indicates anterior-to-pos-terior runway movement produced by locomotorthrust of the rat. A rising pen excursion indicatesposterior-to-anterior movement of the runway.

temperature, it is likely that a study ofthe temperature coefficients of reflexeswas his primary concern (Skinner, 1979,p. 36). It is worth noting that his Par-thenon records also include penciled no-tations of temperature.The torsion-wire recording method was

carried over into yet another device, arunway suspended on tightly drawn,transverse piano wires. The force of thelocomotor thrusts, which constitute therunning of the rat along the runway onits way to the food which Skinner deliv-ered to it at the end ofthe runway, causedthe runway to move slightly along its lon-gitudinal axis, and these slight move-ments were transferred onto a paper ky-mographic record by means of a writinglever connected appropriately to the de-vice, as in Figure 2 ofhis "Case History"(Skinner, 1956a, p. 222). Skinner plannedto deliver a carefully calibrated sound thatwould elicit a sudden halt in locomotion,and to study habituation ofthis reflexivehalt under repeated presentations.

This apparatus, developed in the fallof 1929, lasted into 1931. From this de-vice, he collected celluloid-like gelatinrecords (Skinner, 1979, p. 37) of rat lo-comotion in the fall of 1929. Little or noamplification was used, and the recordsare tiny horizontal squiggles ofone or twomillimeters in amplitude (Folders 1 and6). He recorded latency and amplitude(standard reflex measures) ofthe halt, andhe took the duration of the halt to beanalogous to the after-discharge of re-

flexes reported by reflex physiologists(e.g., Sherrington, 1906/1961, pp. 27-35).In his application for a National Re-search Council (NRC) fellowship in 1930,he included a transcribed record from therunway, demonstrating "the measure-ment ofreflex characteristics in the intactorganism," as the project was titled in hisapplication. Figure 2 is a redrawn portionofthe record that Skinner included in hisNRC application (BFS to NRC, Septem-ber 1, 1930, in uncataloged material ofAccession 9710, Harvard University Ar-chives).The figure shows the small pips that

resulted from footfalls of the rat, and thesudden lurch of the runway that resultedfrom the click. Skinner's objectives were(1) to measure these "reflex characteris-tics" in the intact, freely moving organ-ism, (2) to investigate the phenomenonof habituation to the sound, and (3) "todetermine whether or not the behaviorof the rat was as uniform as that of a'preparation"' (BFS to NRC, September1, 1930, p. 7).In his application for the NRC fellow-

ship, Skinner complained that the wire-supported substrate had a natural fre-quency that was uncomfortably close tothe frequency of rodent footfalls duringa fast run in such a runway (28-32 persecond), threatening an artifactual oscil-lation that would interfere with mea-surement. It appears that the runway alsobounced vertically in response to the up-and-down motion of the running rat(Skinner, 1979, p. 52). Skinner proposedto replace the wires, during his-fellowshipyear, with vertical glass plates whoselength could be so chosen that the oscil-lation frequency of the device would beoutside the range found in rat locomo-tion. In his NRC application, he pro-posed to "amplify the movement elec-trically by means ofa carbon button andan amplifier unit" (BFS to NRC, Septem-ber 1, 1930, p. 10; cf. Skinner, 1956a,Figure 4), but, though Ralph Gerbrandsconstructed the glass-plate device atSkinner's request, "I never got around toelectrical amplification" (B. F. Skinner,personal communication, July 8, 1986).

SKINNER'S QUANTIFICATION 53THE DIVERSITY OF SKINNER'S

RESEARCH

We have gotten a bit ahead ofthe story,chronologically, because the NRC fel-lowship application was made in the fallof 1930. At that point, Skinner had al-ready devised a prototypical operantchamber (which we will describe in thesection called "Breakthrough," below),and he proposed in his NRC application"to carry on both [i.e., the runway andprototype operant chamber] lines of in-vestigation simultaneously" (BFS toNRC, September 1, 1930, p. 4). More-over, he had a third project, which in-volved a running wheel. Therefore, notonly did Skinner make serial modifica-tions in a given class ofapparatus in whichrunways gave rise to the Skinner box-that is the development which he de-scribed in his "Case History" (Skinner,1956a)-but he simultaneously main-tained several lines ofinvestigation usingdistinct apparatus: (1) the runway-to-boxdevelopment (Skinner, 1956a); (2) sus-pended runways which originally werepart ofthe runway-to-box line, but which,for a period oftime, enjoyed a life oftheirown and were used from 1929 into 1930;and (3) the running wheels that he firstused in 1929 and described at length in1933 (Skinner, 1933a).

It is not clear why Skinner abandonedthe suspended runways some time in1931 -he did not mention the runwaysin his application for reappointment fora second year as NRC Fellow (BFS toNRC, December 8, 1931). He certainlyhad not abandoned reflexological ideas(e.g., Skinner, 1931) nor work on loco-motion (e.g., Skinner, 1933a). In fact, thesuccessful measurement of reflex char-acteristics is likely to strike us, knowinghis NRC plans, as a major achievement.The fact that the project "did not go any-where" (cf. Skinner, 1979, pp. 51-53)should appear strange. In setting asidethe runways, he dropped his efforts toassess directly the validity of the reflexas a construct for the description of thebehavior of the freely moving organism(Skinner, 1931). The fact that the archi-

val holdings contain only raw data fromthe wire- and glass-mounted runways andno tables or graphs of dependent vari-ables suggests a mishap of some sort inhis efforts to find quantitative orderlinessor to assess the generality of the conceptofthe reflex (Folders 1 and 6), but we willnot pursue what might be a lengthy tan-gent in trying to resolve that discrepancy.Prof. Skinner offered the simple and di-rect explanation that "I soon turned toplotting ingestion curves [see below,"Quantification"] .... Again it was aquestion of finding which job seemed tobe more important" (B. F. Skinner, per-sonal communication, July 8, 1986). Weoffer, as a friendly amendment, the pos-sibility that "the runway became a run-ning wheel," which we will now elaboratebriefly.

WHEELSSkinner did not begin systematic run-

ning-wheel research until early 1931(Skinner, 1979, pp. 77-78). The researchon the running wheel eventually pro-duced a paper that was completed andreceived in the editorial office ofthe Jour-nal of General Psychology over a yearlater (August 23, 1932) and was pub-lished the following year (Skinner, 1933a).It is his only published paper that usedthe running wheel. This 21 -page paper isswelled by technical exposition of theconstruction of a virtually ideal runningwheel and of the physics of convertingthe forces of rat locomotion on a levelsurface into circular motion. Thoughsomewhat irrelevant to concerns of psy-chologists other than those planning touse a wheel, the physics of locomotionin the wheel sets limits to whether any"running wheel may ... be regarded asa substitute for a level straightaway"(Skinner, 1933a, p. 7). Skinner's physicalexposition, for all its technicality, de-scribed a wheel that could substitute fora runway; the paper included a six-pagesection on fabricating an ideal wheel, re-cording the rat's locomotion, and ar-ranging for the rat to have access to thewheel only for an automatically timed

54 S. R. COLEMAN

period each day. In the construction ofthe wheel, Skinner even made use of in-formation he had obtained from his sus-pended runways, namely the number offootfalls per second (28-32) that are madeby a rat at a "fairly brisk" pace. Theseconsiderations suggest that some of theinterests behind the runway investiga-tions were pursued through running-wheel apparatuses.Offar greater importance for our story,

Skinner gave up the runway's discrete-trial, reflex-type measures in favor of acumulative measure afforded by thewheel. This shift from discrete-trial mea-sures to cumulative and rate measuresalso occurred in the runway-to-box ap-paratus development, and we will de-scribe that shift in the next section. Arunning wheel was the first apparatus toprovide him with quantitative data in theform of a cumulative measure, since ityielded cumulative number of wheel-turns as a function of time. Since Skin-ner's earliest records of running-wheelcumulative data, covering the period June19 to August 4, are on the reverse sideof a June 12, 1929 letter to B. F. Skinnerfrom Harvard Dean Lawrence Mayo(Folder 2), it would seem that Skinnerwas using a cumulative behavioral mea-sure in a portion of his research as earlyas June of 1929. He did not publish re-sults from his running wheel research un-til somewhat later (Skinner, 1933a), andhe did not obtain the data for that pub-lication until the spring of 1931, by whichtime he had already developed a versionof the operant chamber. The running-wheel project was probably of secondaryimportance even at the time, and he doesnot even mention it in his "Case History"(Skinner, 1956a). Nonetheless, though therecords do not permit proof of the asser-tion, it is possible that he borrowed therunning wheel paradigm-that is, cu-mulative performance as a function oftime-for his other research. We can, atthe bare minimum, say that he had al-ready done cumulative recording beforehe applied that measurement paradigmto the operant-chamber prototypes.We will not try to determine which

shift-that in the runway-to-box line or

that in the runway-to-wheel line-hadcausal priority in Skinner's development.The most conservative interpretation isthat Skinner's different apparatuses werea source ofmutual influence in his searchfor quantitative behavioral order.

TEMPORAL BEHAVIORALMEASURES

In describing all three concurrent linesof investigation and their possible inter-dependence, we have gotten as much astwo years ahead of our chronology.Therefore, let us return to the fall of 1929in the runway-to-Skinner-box line of de-velopment, about which Skinner haswritten (Skinner, 1 956a). Around thattime, Skinner devised yet another ap-paratus in the runway-to-Skinner-boxdevelopment, a double runway that per-mitted the rat to go from starting pointto goal box and then to return down aback alley to the starting point, fromwhich it could repeat the cycle.4 The rec-ords are dated in the original hand toNovember, 1929 (Folder 6). Skinner'sprocedure was to start a clock at the be-ginning ofa session and to note manuallythe time of each return to the startingpoint as the clock continued to run. Healso transcribed a stream of naturalisticobservations, for example, that the rat"stopped at other end before comingdown [the back alley]," showed a "sud-den start" or a "very smooth run," ex-hibited "gnawing in the food box," orwas observed to "run hesitant [sic]." And,of course, he caused various noises, in-cluding conversation, to occur during therat's running, thus continuing his earlierinterest in noise-elicited disturbance oflocomotion. When Skinner plotted therun time against the ordinal number ofthe run, he found a wavelike function, asthe facsimile in Figure 3 shows, with hisfree-hand smooth curve passing throughmost of the data points (Folder 6).

Skinner would have been aware that

4It is possible that "the running wheel became adouble runway," since the double runway permit-ted continual locomotion as in a wheel, but we willnot attempt to decide which apparatus had causalpriority.

SKINNER'S QUANTIFICATION 55S00

700

600

1500 .

j400 .

I *I|I IL_Jc 300

-100\/

2 5 10 1S

[Runs]Figure 3. Time to complete one run in the doublerunway as a function ofrepeated runs (trials). Skin-ner drew the free-hand complex curve through thedata points. Redrawn from similar figure withoutaxis labels; brackets indicate that axis labels wereadded.

periodicity was a subject of interest tophysiologists, and that very convincinginstances of it had already been dem-onstrated, since he was acquainted withliterature that reported such findings (e.g.,Richter, 1927, pp. 320-328; cf. the much-cited data on activity and oestrus cyclein the rat, reported in Wang, 1923).Alerted perhaps by such reading, Skinnermeasured the time between the succes-sive peaks of this wavelike function andplotted the times against the ordinalnumber of the peak (Folder 6). Folder 6contains one plot, showing a linear in-crease; other data (unplotted in Folder 6)show a roughly flat function and a neg-atively accelerated increase, with markedindividual differences in the means (fig-ures not shown). These findings wouldhave precluded regarding the inter-peakscore as significant. After making sepa-rate plots ofdaily sequences ofrun times,however, he did find that the center ofthe daily distribution decreased over thefive days of the experiment (Folder 6; cf.

FIS

Figure 4. Redrawn section of a representativekymographic decreasing cumulative record in tilt-box apparatus, from rat #19 on February 25, 1930.Each downward deflection represents completionof one run, and a horizontal section indicates thepassage of time.

Skinner, 1956a, p. 224), which meantthat, despite the trial-to-trial fluctuationsthat are apparent in Figure 3, the speedof his rats increased during training.Moreover-and this is the point we wouldlike to emphasize-the results showedthat his explorations had reached beyondreflex-type, individual-trial, behavioralmeasures to encompass behavioral pro-cesses that are distributed through time-processes which he called, at that stage,"secondary" changes (Skinner, 1931, pp.451-454) and, still later, "dynamic"changes (Skinner, 1938, pp. 14-15). Thisshift to"dynamic" measures was clearlyexemplified by his next research project.

In the winter of 1930 and immediatelyupon the heels of the double-runway ex-periment, Skinner developed a mecha-nized version of the double runway thathe called a "tilt box." A transverse, cen-trally located rod turned the double run-way into a device that resembled a play-ground see-saw. The tilting ofthe runway,which resulted from the rat's locomotioninto successive sections of the runway,caused a spindle-mounted slotted disk torotate and thereby to dispense a food pel-let automatically into the food cup, andalso to change the position of a writinglever so that a decreasing cumulative rec-ord resulted (Skinner, 1956a, p. 225). Arepresentative example of such a recordis the redrawn record in Figure 4 (fromFolder 4). With this apparatus develop-ment, Skinner had at least replaced hand-recording oftimes with a mechanical de-vice. More important for the theme ofthe present paper, it is apparent that he

56 S. R. COLEMAN

120

co

2908

600- *'

C~~~~~~~~~~~~~~~~~~~~IC

o Time 2 a. Grams 0

DaysFigure 5. Summary curve plotting the duration ofa 50-run tilt-box session (in open circles) as a functionof days, and amount of food given on the preceding day (in filled circles). Redrawn from similar figurein Folder 4.

had abandoned trial-to-trial times, be-cause the cumulative records have no sig-nal-marker to register time. Though hecould later have calculated the trial-to-trial times from the known speed of therotating drum, he had no simple, im-mediate, and effortless way of retrievingtrial-to-trial times from the records.Someone whose scientific conduct wasunder the control of contingencies in-volving expenditure of effort (Skinner,1 956a, p. 224) would surely have reducedeffort by employing a time signal-markerin the kymographic record, if he wereinterested in those values. After all, hehad used such a marker in the recordsfrom the Parthenon and suspended-run-way research. Instead, he drew straightlines to approximately straight sectionsof the cumulative record, as Figure 4shows-an "eyeball" technique that heand Barnes had employed in their antstudy (Barnes & Skinner, 1930). Skin-ner's use of this technique further sup-ports the suggestion that he had becomeconcerned with "dynamic" changes inperformance that do not require the cal-culation of instance-to-instance scores.

Furthermore, his summary curves fromthe tilt-box experiment plotted the lengthof time needed to complete 50 runs, asummarizing statistic rather than a trial-to-trial measure, as Figure 5 shows. Fig-

ure 5 is a redrawn version of one of thefigures that have survived from his tilt-box research (in Folder 4). The figure plotsthe duration of daily 50-run sessionsagainst days (in open circles), and alsothe amount offood consumed on the pre-ceding day (in filled circles). Clearly, hewas looking for a correlation between asummarizing performance measure andmotivational level (hunger), but the re-lationship that he discovered was not veryconsistent. (Despite marked variability,a decrease in session length as a functionof days is discernible in the figure.)

BREAKTHROUGHThe irregular data in Figure 5 are not

likely to suggest that in early March, 1930Skinner was about to experience a majorbreakthrough in his research that resultedin the kind of conditioning preparationon which he then concentrated with onlyminor apparatus modifications for sev-eral years. On the other hand, ifhis strat-egy were to abandon projects or devicesthat did not yield quantitative regulari-ty-as has been intimated thus far, andas assumed in making sense of the aban-donment of the Parthenon-then at thispoint in time he would at least have beenready for another apparatus change. The

SKINNER'S QUANTIFICATION 57

too to, troo /so 5so so0

IHR. 21W. f MW. 2t-. /MR. 2W.# W-2S #*4s-26 45-27

Figure 6. Copy of cumulative records of panel pressing. Cumulative number of presses on ordinate,time on abscissa. Data from rat #45, March 25, 26, and 27, 1930.

following steps appear decisive in hissubsequent development.The essential first step for Skinner was

to recognize that his behavioral prepa-rations had all suffered from excessivevariability and that he needed to controla variety ofdisturbances. He already hadplenty of experience with this kind ofproblem, having read Pavlov (e.g., Pav-lov, 1927/1960, pp. 44-46) and havinghimself investigated the interfering effectof noise upon locomotion in several dif-ferent apparatuses. The next step was toconstruct soundproofed boxes in whichhis behavioral apparatus would be placed.Since he had already devised free-re-sponding apparatus (as opposed to hisearlier trial-by-trial equipment), he hadat least developed the kind ofapparatusthat could be run without the supervisingand potentially interfering presence oftheexperimenter. Finally, Skinner shortenedthe length ofthe repetitive behavioral se-quence ending in food ingestion, by re-quiring no locomotion at all. He choseto study hunger motivation, an impor-tant physiological and psychological top-ic of the period. Hunger was a subject inwhich he had done some reading (e.g.,Cannon, 1915; Richter, 1927)-interest-ingly, he purchased Cannon's book inNovember of 1929, according to the fly-leaf date in Prof. Skinner's personalcopy -and, ofcourse, he hadjust finishedinvestigating the influence of hunger inhis immediately preceding research proj-ect.

Skinner constructed a small chamberthat required the 24-hour food-deprivedrat to press against a small panel to ex-pose a tray offood behind the panel, fromwhich it could reach in and withdraw asingle pellet offood, and then eat it. Thissequence could be repeated over and over,with kymographic equipment recordingeach panel-press. The chamber wasplaced inside the soundproofed box, thusshielding it from outside disturbances,including the sounds made by the re-cording equipment.According to his later account (Skin-

ner, 1956a), he made a rotating spindlelift a writing lever (instead of loweringthe lever, as he did for Fig. 4, above), andhe produced cumulative records (cf. fig-ures 10 and 11 in Skinner, 1956a), whichhe called "ingestion curves" at that point,because the curves displayed the time-course of ingestive behavior. Figure 6shows several "ingestion curves," whichplot against time (t) the cumulative num-ber (N) ofpieces offood taken in a sessionthat typically lasted one to two hours(Folder 5). His earliest "ingestion curves"were based on rats #45 and #50, whichanimals he also used in his tilt-box re-search. The earliest records offood inges-tion were obtained in early March, 1930.Skinner would surely have observed thatthese records were the simplest that hehad thus far obtained, and that the gen-eral shape of the function, a concave-down function, was approximately thesame from rat to rat and from day to day.

58 S. R. COLEMAN

240

200 #45, day 26 (obtained)#45, day 25 (idealized)-#45, day 25 (obtained) ,

160-

N2 120

80

40

2 4 6 8 10 12

Time (t)Figure 7. "Square plot" of cumulative responses(N) in panel-press apparatus, for rat #45 on March25 and 26, 1930. Figure plotted from Skinner's ta-bles ofnumerical values obtained from kymograph-ic records.

The only question would be: What is thefunction that describes these data?

QUANTIFICATIONSkinner's quantitative manipulation of

his cumulative records was primarily in-tended to linearize them. Some curves(e.g., power, log, and exponential func-tions, hyperbolas, and others) can be lin-earized, while others cannot (Daniel &Wood, 1971, pp. 19-24). Equations forlinearizable curves are obtainable throughsimple algebraic techniques, and func-tion-fitting can be done with least-squaresprocedures. Since Skinner had no ideawhether his cumulative records were lin-earizable, he tried out several transfor-mations. His efforts show a pattern ofexploration, some of it unorthodox, likethat which we have seen in his explora-tion of alternative apparatus. In the rec-ords dated to the middle ofMarch, 1930,he was trying out a y-squared transfor-mation by plotting against time (t) thesquare of the number (N) of pellets in-gested by each rat (see Skinner, 1979, p.59), perhaps because the records in Fig-ure 6 look as though they might be square-root functions. The archival records(Folder 5) contain a number of these"square plots" both of observed perfor-mance and also of the idealized perfor-

mance that would have resulted if theobtained cumulative record had notshown irregularities (Skinner, 1933b, pp.311-318; cf. Skinner, 1979, pp. 58-60).

Figure 7 contains "square plots" ofSkinner's tabled values of observed per-formance for one of his rats on two suc-cessive days (filled circles and trianglesin the figure), and of idealized perfor-mance (in open triangles). Assuming hecompared his square plots,5 he wouldhave found that there was considerablevariation in a given rat's square plot fromday to day (as a comparison of the func-tions with filled data points in Figure 7shows) and, moreover, that the obtaineddata departed from a straight-line ideal-ization (as a comparison ofopen and filledtriangles in the figure also shows). Hewould thereby have discovered that thesquare transformation did not smooth outday-to-day fluctuations in a given rat'sperformance. Since his observed-datasquare plots did not conform to a straightline, he would legitimately have conclud-ed that his observed cumulative data de-parted from a form resembling the pos-itive limb of the function N = k Vt.By the end of March, 1930, he began

to use common logarithms, and his tablesof data (Folder 5) extracted from cu-mulative records included both the squareof the number of pieces eaten (i.e., N2 inFig. 7) and the logs ofN and time (t). Inplotting the data of rats #45 and #50 forseveral days in log-log coordinates, theapproximately straight lines showed thathis cumulative records conformed to apower function of time, N= ktn, with theslope (the exponent, n, ofthe power func-tion) ofthe lines approximately the same(n = .68) from day to day and from onerat to another, as is apparent in Figure 8.Figure 8 reproduces, with permission ofProf. Skinner, the second figure from the

I Each square plot in Skinner's records in Folder5 is for a given rat on a given day. None of therecords plots data for several rats on the same day,or for a given rat on successive days, though Skinnercould easily have superimposed these graph-paperfigures and held them up to strong light to comparethem. Such comparison is provided for in Figure7, which depicts data that exist only in a tabularformat in the archival materials.

SKINNER'S QUANTIFICATION 59

12

,8

nl .2 .4 .6 .8./- 12 L#

Zeo~~~~~~A- AtFigure 8. Original caption: "Five records for each of the animals in figure 1, plotted on logarithmiccoordinates (units arbitrary). The slope of the four limiting straight lines is for n = 0.68." Note. Figurereproduced from Skinner, 1930, Figure 2, with permission of Prof. Skinner.

Proceedings of the National Academy ofSciences, in which he published his find-ings (Skinner, 1930).

It would be quixotic to trace out thesources for such transformations as thelogarithmic, as part ofthe task ofmakingsense of Skinner's quantitative manipu-lations, since logarithms were widely usedin the biological-physiological literaturewith which he was acquainted, especiallythe publications of Crozier and his stu-dents (e.g., Crozier, 1928). Moreover, thesquare and logarithmic transformationsmade up a standard procedure for theanalysis of data in biological, physical,and engineering work (Cuthbert Daniel,personal communication, June 28, 1986).Since Skinner was getting help from Dan-iel in quantitative matters (Skinner, 1979,

pp. 59-60, 67), he was at least followinginstructions. Other evidence indicatesthat Skinner did a bit of exploration onhis own. For instance, from the same data(rats #45 and #50 on March 25 and 26,1930) on which he was making logarith-mic transformations, he also obtained anunusual ratio. The ratio was obtained bychoosing a handful ofvalues (in arbitrarygraph-paper units) along the time axis,and drawing tangents to the cumulativerecord at these time points, as Figure 9shows. Figure 9 is a redrawn figure fromone of the archival records (Folder 5),showing an ingestion curve with tangentlines drawn at numbered time points.

Skinner measured the angles of thesetangents, then obtained the ratio of eachangle (in degrees) to the height (in arbi-

60 S. R. COLEMAN

4 8

14~~~~~~~

142

10Rat #45

N 8 Day 27

6

4

2

0 2 4 6 8 10 12 14

TimeFigure 9. Redrawn panel-press cumulative recordfor rat #45 on March 27, 1930; cumulative number(N) of presses as a function of time, with arbitraryvalues on both axes of graph-paper original figure.Labeled tangents are drawn to the record at t = 1,2, 4, and 8.

trary graph-paper units) of the cumula-tive record at the point of tangency. Thisratio is a rather unorthodox instrumentfor analyzing a function. Moreover, itmisses the point with regard to changesin slope as afunction oftime, because thenumerator and denominator both reflectvalues of N, the cumulative number ofpieces of food eaten. Perhaps Skinnerwished to determine how the momentaryrate ofeating (angle oftangent) dependedon how much food had already been con-sumed (height of curve). An appropriateresearch history existed for such a ques-tion, since the relationship of perfor-mance to amount of consumed food wasthe subject of interest in part of his tilt-box research, as Figure 5 showed. If thatwere his objective, he would have donebetter to plot the angle or its tangentagainst the height,6 instead of forming a

6 Had he calculated and then plotted the tangentof the angle as a function either of time or of theheight of the curve at the point of tangency, hewould have found nonlinear curves with large be-tween-subject and between-day variation (figure notshown), which would have been grounds for aban-donment of the technique, according to our inter-pretation.

30 A

25

20

C \\t#50, day 27Q / #45, day 2615_\ # #45, day 27

.2

10

5

2 4 6 8 10 12

Tin (t)Figure 10. Data for rat #45 on March 26 and 27,and for #50 on March 27, 1930. Ratio of angle oftangent to height of the point of tangency on therespective cumulative records is plotted against time.See text and Figure 9 for method of calculating.

ratio of variables (angle and time) thatchange in opposite directions. Though theratio that he calculated appears to bewithout an easily recovered rationale,elaborate second-guessing may be point-less, because surviving records (Folder 5)contain no plots of this ratio, or of thelogarithm ofthe ratio, which Skinner alsocalculated in his tables of data. Ifhe hadplotted his tabled data, he would havefound that he had not linearized his cu-mulative records and that both the ratioand its logarithm showed between-sub-ject variability in form and slope, as Fig-ures 10 and 11 show. He would havebeen forced to the conclusion that theangular ratio was no improvement overthe square and log functions that he wastrying out about the same time.

If Skinner's conduct as a scientist in-volved widely ranging exploration withsubsequent rejection of "unprofitableline[s] ofattack" (Skinner, 1956a, p. 221)and sustained involvement in the prof-itable lines, then he would have tried avariety ofquantitative manipulations andabandoned all but the successful ones.Indeed, the archival records show thatduring March, 1930, he tried all three

SKINNER'S QUANTIFICATION 61

1A

#50, day 271.2O day 26#45, day 27

Ia -OA

OA _-\

0.2 -

I I I I I I I I2 4 6 8 10 12

Thu (t)Figure 1 1. Plot ofthe logarithmic transformationsof the ratio values in Figure 10, against time.

quantitative transformations (square, log-log, and angular ratio) on the same data(Folder 5), but published only the loga-rithmic data (Skinner, 1930).

CONCLUSIONWhen Skinner discovered that the

power function he had obtained from hispanel-pressing rats showed constancy ofthe exponent (n = .68) across rats anddays-as Figure 8 showed -and when hesubsequently found that power functionswith the same exponent could also beobtained from lever-pressing rats (re-ported in Skinner, 1932b), then he hadindeed obtained the generalizable quan-titative orderliness that he had been seek-ing.7 A period of frequent apparatuschange during the fall and winter of 1929-1930 came to an end. Though he sub-

7 The fact that Skinner eventually became disen-chanted with the possibility of a general functionfor satiation of hunger-motivated behavior is ir-relevant (Skinner, 1938, pp. 350-351). Well before1938, his research program in lever-press behaviorwas solidly established and independent of his ear-lier research topics of tropisms, locomotion, andhunger. The excessive significance he initially at-tached to his power function (Skinner, 1930, p. 438;1932b, pp. 47-48) had led to favorable outcomesthat he did not originally anticipate, a feature thatis no doubt a variant ofserendipity (Skinner, 1 956a,p. 227).

sequently made technical improvements,he made no further substantive alter-ations of his lever-press apparatus formany years, and the device became thestandard preparation for studying oper-ant behavior.

Elsewhere we have pointed out variousmetatheoretical consequences of his dis-coveries of quantitative regularity, suchas a neutralization ofthe problem ofvari-ability, the vindication ofgeneric (molar)concepts, and a shift from a Nominalisticto a Realistic ontology (Coleman, 1984).For our presently more limited concernswith apparatus and projects, it is reason-able to conclude that Skinner's early re-search program exemplified a unifyingstrategy of seeking quantitative behav-ioral orderliness, and that his success andfailure in this endeavor was an importantfactor in the development of his behav-ioral apparatus and research projects.

SKINNER'S LATERQUANTITATIVE WORK

As is well known, Skinner's quantita-tive emphasis has never been thorough-going. In his 1930 paper, though he cal-culated constants for his power function(and its derivatives), the particular nu-merical values were not utilized in fur-ther quantitative elaborations (Skinner,1930). This clearly set his research pro-gram apart from that of Crozier. It is alikely inference that it was not the specificquantitative values (e.g., an exponent of.68) that were important to Skinner, butrather thefact that quantitative regularitywas actually exhibited. This interpreta-tion supports our proposal (Coleman,1984) that Skinner's early research pro-gram had strongly philosophical agenda,which included the defense of determin-ism (or lawfulness: cf. Scharff, 1982) andthe operational clarification of psycho-logical concepts, in this case, "hungerdrive" (cf. remarks on the status of theconcept of hunger in Skinner, 1930, pp.433-434; 1931, p. 454; 1932a, pp. 33-34). Though the same exponent of hispower function (n = .68) turned up insubsequent lever-press research (Skin-ner, 1932b), again he did nothing withthe particular value of the exponent ex-

62 S. R. COLEMAN

cept to note the regularity and to drawimportant but nonquantitative conclu-sions (Skinner, 1932b, pp. 47-48).For a number of years, Skinner pe-

riodically tried quantitative attacks onresearchable questions. His empiricalwork in the psychology ofliterature (e.g.,Skinner, 1939, 1941) involved the cal-culation of probabilities. In the study ofextinction, he employed curve-fittingagain and proposed that his extinctioncurves were logarithmic, connecting thispossibility with a fluid-reservoir modelof extinction processes (Skinner, 1938,pp. 26-28, 83-96, et passim). But hismodel-building succumbed to quantita-tive criticism (e.g., Ellson, 1939) and em-pirical difficulties (e.g., Skinner, 1938, p.416; 1940). Though it seems safe to haz-ard the guess that Skinner had neither thehighly developed quantitative skill northe required convictions8 to go far downthe quantitative road, that is primarily aconjecture about events that are outsidethe chronological frame ofthis article andbetter left to future investigations.RECONSIDERATION: VARIETIES

OF PROGRESSOur account and our conclusion cer-

tainly suggest something like progress inSkinner's early research program, not ina straight-line succession of improve-ments but at least in an inefficient, evo-lutionary fashion. Skinner's "Case His-tory" adduces factors, such as luck andaccident, that were responsible for prog-ress despite their apparent haphazard-ness. The present account places moreemphasis on a unifying mechanism: Heabandoned projects and apparatus thatdid not lead to quantitative orderliness;he pursued projects that yielded such reg-ularity; and he made progress in the sensethat his search resulted in the successful

8 In response to a query about his commitmentto curve fitting and other quantitative techniques,Prof. Skinner described hearing Cuthbert Danielsay in conversation many years ago that "with threeconstants in an equation you can draw an elephant,and with four you can make him lift his trunk" (B.F. Skinner, personal communication, July 9, 1985;cf. Skinner, 1944, pp. 280-281; 1956c).

determination of the power law of satia-tion. But such a balance sheet of accom-plishments presents an abstractive andunidimensional picture of Skinner'sprogress. We will briefly suggest two ad-ditional aspects ofhis progress or success,and will leave the door open for more.

First ofall, Skinner's successful choicesof apparatus and project did not alwaysinvolve shifting to a line of investigationthat brought him closer to a specific, pre-viously established research goal. For in-stance, in setting aside his suspendedrunways, Skinner moved away from whatlooked to be a successful line of runwayresearch that was testing the validity ofthe reflex in its application to the freelymoving organism. Instead, he switchedto a project, one involving ingestioncurves obtained in the panel-press ap-paratus, that immediately gave rise tofur-ther related activities. His ingestion curvesprompted efforts at linearization, whichtook him away from the runways (seeSkinner's remarks above, "The Diversityof Skinner's Research"). The panel-pressapparatus very soon required some tech-nical improvements (e.g., a device to pre-vent contact chatter), which involved himin shop work, an activity that already wasvery appealing to him. The "successful"project, that is, created further projectsthat engaged Skinner's concern, time, andeffort.As a final example: Beginning in No-

vember, 1931, Skinner kept notebookscalled "Protocols" (presently located inFolder 7) which listed his rats by numberand their experimental treatments, andincluded notations to accompany the cu-mulative records generated by each rat.9The fact that the Protocols also included

9 The records, smoked paper sheets mounted ona slowly moving kymograph-drum, could not easilybe written upon during a session. On the occasionof an apparatus malfunction or an experimentalerror (such as a failure of the feeder to operate), itwas necessary to make a note in the Protocol toindicate this and the time ofits occurrence. Skinnernoted in the Protocol the time at which the kymo-graphs were started, so that the malfunction or dis-turbance could be pinpointed upon the cumulativerecord, and the effect ofthe disturbance on respond-ing could be ascertained.

SKINNER'S QUANTIFICATION 63

ideas for future experiments with thesame apparatus, and the fact that he sub-sequently carried out many ofthe plannedprojects, indicate that his prototype Skin-ner-box effectively limited his apparatusexplorations by monopolizing his time.It seems apparent that the "successful"project or apparatus was typically one thatkept the researcher involved so that var-ious other, quite different and unrelatedprojects could not be started.A second aspect of progress is less ob-

vious and may owe more to interpre-tation. The basic idea is that Skinner'sdevelopment showed an abstract-to-con-crete direction, and that his progress orsuccess consisted in choosing alterna-tives that brought him into more im-mediate contact with more concretelycompelling findings (cf. Skinner, 1986).In terms of this consideration, Skinner'searliest research projects were quite de-fective. The collaborative project with T.C. Barnes was not entirely his own, andthe squirrel project with Dwight Chap-man involved ideas that Skinner foundrepugnant (cf. the skit described in Skin-ner, 1979, p. 31), reducing the likelihoodofdeeply personal involvement and find-ings. It is true that the Parthenon engagedhis established commitment to reflexo-logical ideas, as did the "posture in babyrats" project, but his findings were notconcretely pertinent to specific researchobjectives, because neither seems to haveyielded data that showed enough regu-larity (see above). As a result, Skinner'stheorizing about rat behavior in the Par-thenon was thin and abstract, merelyspeculative and derived mostly frombooks and articles (Skinner, 1979, pp. 33-34). His suspended runways yielded a va-riety ofdependent variables (latency, du-ration, amplitude, and R/S ratio) thatcould have been significant in relation tohis reflexological ideas; but his doublerunway was a better apparatus, becauseit gave him data that showed a dynamicchange in running speed which he couldsee in the succession of daily distribu-tions ofrunning times. The fortunate ac-cident that he left the spindle on a wood-en pellet-delivery disk (Skinner, 1956a,p. 225) yielded him what was at that time

his most effectively concretized represen-tation of an orderly behavioral change(see Fig. 4). In temporal charts like Figure4, Skinner made a dynamic process con-crete, and thus the results of his researchwere immediately and almost tangiblyinspectable.The subsequent apparatus develop-

ments in the runway-to-box line were ad-mittedly "steps closer toward behaviorallaws," but, in comparison to the devel-opment of the cumulative curve (Fig. 4),and from the standpoint of this secondaspect of progress, they look almost an-ticlimactic. As Skinner was soon to claim,the virtue of the cumulative record wasthat it afforded something that "is in ef-fect .. . the description of a process [ofsatiation of "the facilitating condition"of hunger]" (Skinner, 1930, p. 437). Tosomeone seeking behavioral orderliness,an inspectable display of it must havebeen a powerful payoff. Years later heremarked: "In choosing rate of respond-ing as a basic datum and in recording thisconveniently in a cumulative curve, wemake important temporal aspects of be-havior visible" (Skinner, 1956a, p. 229,emphasis original). The development inwhich Skinner's activities were influ-enced less by abstract concerns and moreby concrete findings was, for Skinner, achange that probably ought to be calledprogressive. Other facets of "progress,"either idiosyncratic to Skinner or gener-alizable to the careers of other scientists,remain to be delineated.

RECONSIDERATION: HAPPYENDINGS

Even ifwe allow that the idea of prog-ress in a research program may admit ofdistinguishable facets, we would still wantto return to a balance sheet of accom-plishments and to say that Skinner madeprogress in the sense that his search forquantitative regularity ended in the dis-covery of a power law for satiation ofhunger in panel-pressing rats (Skinner,1930) and later in lever-pressing rats(Skinner, 1932b). If only Skinner hadconfined his subsequent labors to the le-ver-press apparatus, we might regard the

64 S. R. COLEMAN

discovery of generalizable regularity inthe lever-box in 1931 as a happy endingfor our story, since the lever box couldbe seen as terminating the early researchprogram and initiating an operant-con-ditioning research program.

Skinner, however, continued to pursuelocomotion and reflex-type research in avariety of ways (as we already remarkedin "The Diversity of Skinner's Re-search"), which shows that other linescontinued to exist alongside the runway-to-box line of apparatus development inhis early research program. His aban-donment of a reflexological program-aprogram that included empirical workwith runways, reflex-theoretical workwith boxes (e.g., Skinner, 1931; 1932a,pp. 31-32; 1932b, pp. 38-39), historicalresearch on the reflex (Skinner, 1931;Skinner & Crozier, 1931), and even atranslation project on Magnus (1924) inthe spring of 1930-was a protracted af-fair, by no means complete by the timehis development ofthe lever box had ter-minated his explorations in one partic-ular line ofapparatus development in histhree-part enterprise. Moreover, he wasinvolved in a spinal-reflex project at theHarvard Medical School during 1932-1933, and he did not publish the dis-tinction between lever-press behavior(operant) and true reflexes (respondents)until 1935. Finally, the very concept ofoperant behavior was developed in acontext oftheoretical considerations thatsimply were not operative in 1931, as wehave previously shown (Coleman, 1981).To think his early research program hadthe happy and singular consequence ofopening up an "operant conditioning"line ofinvestigation in 1931 would clear-ly be a case of reading a later develop-ment back into the earlier stages, asthough a program of operant condition-ing research were an objective ofhis earlyresearch program of 1928-1931. Suchthinking is the result of standing uponthe vantage point of his later operant-conditioning research and regarding hisearly program as unified by virtue ofserving to bring about the later program.The importance of accident and luck in

Skinner's development (Skinner, 1956a)shows that such a vision of at least hisscientific development is an idealization.Our emphasis on the diversity of Skin-ner's early research program shows thesame.Two suggestions seem appropriate to

end this piece. First of all, the immediateand strong appeal of happy endings ob-scures the fact that such endings are in-ventions that increase the apparent co-herence ofthe onlooker's story, rather thansimply neutral-descriptive conclusionsregarding the subject under study. Evenfor all of its emphasis on centrifugal fac-tors, Skinner's (1956a) "Case History" isa success story in which the lever box wasthe primary achievement. Moreover,Skinner (1956a) reduced the apparent di-versity of his early research program byfocusing upon the runway-to-box devel-opment, by omitting discussion of therunning wheel research, and by treatingthe runways as only a phase in the de-velopment of the lever box. Though thephrase sounds hackneyed when it occursin a conclusion, our account suggests thatSkinner's early research program was ac-tually a bit more complicated than hisportrayals indicate (Skinner, 1956a, 1967,1979), and such complications makehappy endings look artificial.

Secondly, the satisfaction afforded bya tidy and complete story of a personaldevelopment can serve as a powerful trapthat prematurely brings the biographicalexploration to a halt (cf. the remarks onmentalistic explanation, in Skinner,1956b, pp. 81-84). Having made senseof the development, we are tempted tolook no further. This danger may be anintrinsic feature of historical-biographi-cal interpretation, since it leans towardcircumstantial coherence as a touchstoneof interpretative adequacy, but an eval-uation of that possibility is not requiredhere. Moreover, by closing the presentarticle with mildly skeptical reflectionsand with suggestive possibilities, weclearly leave open the question whetherdifferent considerations will make evenbetter sense of Skinner's early researchprogram.

SKINNER'S QUANTIFICATION 65

REFERENCESBarnes, T. C., & Skinner, B.F. (1930). The pro-

gressive increase in the geotropic response of theant Aphaenogaster. Journal of General Psychol-ogy, 4, 102-112.

Bixenstine, V. E. (1964). Empiricism in latter-daybehavioral science. Science, 145, 464-467.

Cannon, W. B. (1915). Bodily changes in pain,hunger, fear and rage. New York: Appleton.

Coleman, S. R. (1981). Historical context and sys-tematic functions of the concept of the operant.Behaviorism, 9, 207-226.

Coleman, S. R. (1984). Background and changein B. F. Skinner's metatheory from 1930 to 1938.Journal ofMind and Behavior, 5, 471-500.

Coleman, S. R. (1985). B. F. Skinner, 1926-1928:From literature to psychology. Behavior Analyst,8, 77-92.

Crozier, W. J. (1928). Tropisms. Journal GeneralPsychology, 1, 213-218.

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