The Contingent Smile: The Contingent Smile: A Meta-Analysis of Sex A Meta-Analysis of Sex Differences in SmilingDifferences in Smiling

Marianne LaFrance, Marvin Marianne LaFrance, Marvin Hecht, & Elizabeth Levy Hecht, & Elizabeth Levy

PaluckPaluckPresented by: Mandy McCoy

PurposePurpose

To determine if there are gender To determine if there are gender differences in smilingdifferences in smiling

Literature ReviewLiterature Review

MethodsMethods– Electronic Sources (Key words: smile, Electronic Sources (Key words: smile,

smiles, and smiling)smiles, and smiling) PsycINFO (1967-2001)PsycINFO (1967-2001) Sociofile (1974-2001)Sociofile (1974-2001) MEDLINE (1975-2001)MEDLINE (1975-2001) ERIC (1966-2001)ERIC (1966-2001) Social Science Citation Index (1973-2001)Social Science Citation Index (1973-2001) Antrhopological Index (1975-2001)Antrhopological Index (1975-2001) Dissertations Abstracts International (1861-2001)Dissertations Abstracts International (1861-2001)

– Other abstract references Other abstract references unavailable electronically using the unavailable electronically using the same key words as well as same key words as well as nonverbal communication and facial nonverbal communication and facial expressionexpression

– Reference ListsReference Lists

Literature ReviewLiterature Review

– Conference Programs (through 2000)Conference Programs (through 2000) American Psychological AssociationAmerican Psychological Association American Psychological SocietyAmerican Psychological Society Western Psychological AssociationWestern Psychological Association Eastern Psychological AssociationEastern Psychological Association Midwestern Psychological AssociationMidwestern Psychological Association Rocky Mountain Psychological Rocky Mountain Psychological

AssociationAssociation Society for Personality and Social Society for Personality and Social

PsychologyPsychology

Literature ReviewLiterature Review

– Previous meta-analysis studiesPrevious meta-analysis studies– Ancestry MethodAncestry Method

Reference lists of retrieved studies Reference lists of retrieved studies scanned for additional reportsscanned for additional reports

– Invisible college methodInvisible college method Individual investigators known to have Individual investigators known to have

conducted research on facial expression conducted research on facial expression and nonverbal behavior contacted via e-and nonverbal behavior contacted via e-mailmail

Literature ReviewLiterature Review

Criteria for Selected Criteria for Selected StudiesStudies

Must be a measure of smiling by Must be a measure of smiling by both sexesboth sexes– Measure could be smile frequency, Measure could be smile frequency,

smile duration, or ratings of facial smile duration, or ratings of facial pleasantnesspleasantness

Studies in which participants were Studies in which participants were instructed to smile were excludedinstructed to smile were excluded

Studies of children under age 13 Studies of children under age 13 were excludedwere excluded

VariablesVariables

30 variables were coded and 30 variables were coded and measured for reliabilitymeasured for reliability

Reliability ranged from .71 to 1.00Reliability ranged from .71 to 1.00

ModeratorsModerators

Observation awarenessObservation awareness Presence of othersPresence of others Engagement with othersEngagement with others Instructions to get acquaintedInstructions to get acquainted Research settingResearch setting Archival materialArchival material FamiliarityFamiliarity Overall constraintOverall constraint

ModeratorsModerators

PowerPower Caretaking roleCaretaking role TeachingTeaching InterviewInterview DeceptionDeception CompetitionCompetition ConflictConflict PersuasionPersuasion

ModeratorsModerators

Social tensionSocial tension Task tensionTask tension Self-disclosureSelf-disclosure EmbarrassmentEmbarrassment SadnessSadness HappinessHappiness HumorHumor

ResultsResults

Total # of Total # of participantsparticipants

109,654109,654

Research reportsResearch reports 162162

kk 418*418*

dd .41.41

95% CI95% CI .39-.42.39-.42

d d (including (including assigned zeros)assigned zeros)

.40.40

Unweighted mean Unweighted mean dd .38.38

Unweighted median Unweighted median dd

.41.41

* k = 448 effect size including assigned zeros

Regression Coefficients Regression Coefficients Between Moderators and Between Moderators and

Smiling DifferencesSmiling Differences

Instructions to get Instructions to get acquaintedacquainted

-.006-.006

CompetitionCompetition .002.002

SadnessSadness .015.015

Moderator β

Regression Coefficients Regression Coefficients Between Moderators and Between Moderators and

Smiling DifferencesSmiling Differences

Engagement with Engagement with othersothers

-.159***-.159***

Research settingResearch setting -.038*-.038*

Social tensionSocial tension -.036**-.036**

* p = .06 ** p < .05 *** p < .01

Moderator β

Regression Coefficients Regression Coefficients Between Moderators Between Moderators

and Smiling and Smiling DifferencesDifferences

Observation Observation awarenessawareness

.163****.163****

Presence of Presence of othersothers

.258****.258****

Archival Archival materialmaterial

-.160****-.160****

FamiliarityFamiliarity .146****.146****

Overall Overall constraintconstraint

-.055****-.055****

PowerPower -.132****-.132****

Caretaking roleCaretaking role .099****.099****

TeachingTeaching -.028****-.028****

**** p < .001

Regression Coefficients Regression Coefficients Between Moderators and Between Moderators and

Smiling DifferencesSmiling DifferencesInterviewInterview .134****.134****

DeceptionDeception -.078****-.078****

ConflictConflict -.118****-.118****

PersuasionPersuasion -.060****-.060****

Task tensionTask tension -.055****-.055****

Self-disclosureSelf-disclosure .165****.165****

EmbarrassmentEmbarrassment -.039****-.039****

HappinessHappiness -.061****-.061****

**** p < .001

Effect sizesEffect sizes

Variation in effect sizes confirmed Variation in effect sizes confirmed by a homogeneity analysisby a homogeneity analysis

QQww(417) = 2,072.01, (417) = 2,072.01, pp < .0001 < .0001

ConclusionsConclusions

The meta-analysis confirms that The meta-analysis confirms that women and adolescent girls smile women and adolescent girls smile more than men and adolescent more than men and adolescent boysboys

Although results were significant, Although results were significant, gender differences in smiling gender differences in smiling depends on a variety of factorsdepends on a variety of factors