Key Terms:

Personality: The thoughts behaviours and feelings that make an individual unique. It remains fairly constant throughout life but can develop as a result of experience.

Temperament: in the inherited parts of personality and it describes how a person responds to the environment. This remains the same throughout life.

Studies of TemperamentThomas Chess and Birch (1977) Buss and Plomin (1984) Kagan and Snidman (1991)Aim: To see whether ways of responding to the environment remain stable throughout life

Aim: To see whether temperament in innate (you are born with it)

Aim: To see whether temperament is due to biology

Method: 133 children in a longitudinal study. Children observed and parents were asked about the child’s routine and reaction to change

Method: 228 MZ twins and 172 DZ twins studied. Temperament of the twins was rated on emotionality, activity and sociability. The twins were compared to each other.

Method: hundreds of 4 month old babies were placed in a new situation – they could not see their caregiver and were shown new toys and their reaction to this measured.

Results: The children fell into three types; ‘easy’ (happy) ‘difficult’ (cried a lot) or ‘slow to warm up’ (did not like change at first)

Results: MZ twins were more similar to each other than the DZ twins

Results: 20% were high reactive (cried a lot) 40% were low reactive (showed little emotion) and the rest were between the two. The tested them 11 years later and the high reactives were shy and the low reactives were calm.

Conclusion: Temperament is innate as their way of responding to the environment stayed the same

Conclusion: Temperament is genetic

Conclusion: Temperament is biological sue to the way the brain responds

Evaluation: As this is a longitudinal

study some of the participants could have dropped out

The children were from middle class families in New York so you cannot generalise to other backgrounds

The parents may have given socially desirable answers in the interviews

Evaluation: MZ twins may be treated

more similarly than DZ twins – e.g. dressed the same, bought the same presents etc...

Testing twins is the best way to determine whether a characteristic is genetic

You cannot generalise research from twins to non-twins

Evaluation: They used a large sample

size so it is easier to generalise the results

They used an experimental setting to test the children and this may have affected their behaviour so the study lacks ecological validity

It is very easy to miss certain behaviours in children and also they cannot explain why they have behaved in a certain way

How is personality measured?

Eysenck’s Type theory of personality

According to type theory our personality is inherited and different people show different traits. These include:

Extroversion: where people are very sociable and look to others for entertainment Introversion: a person who is happy with their own company Neuroticism: a person who is highly emotional and shows a quick, strong reaction to fear

Eysenck believed that these differences are biological and due to the way in which our nervous system reacts to stress

Key Study: Measurement of Personality

Aim: To investigate the personality of servicemen

Method: Soldiers were given a personality questionnaire and Eysenck analysed the results using factor analysis

Results: He identified two dimensions of personality: extroversion –introversion and neuroticism –stability

Conclusion: Everyone can be placed along these personality scales and most people fall somewhere in the middle.

Evaluation:

His original research was difficult to generalise beyond soldiers, but since then the research has been carried out on thousands of people

The questionnaires may be measuring people’s mood rather than their personality and also people can give socially desirable answers

He ignored environmental factors and did not believe personality could change as a result of experience

Personality Scales:

1) The Eysenck Personality Inventory (EPI)

This measures the dimensions of extroversion-introversion and neuroticism-stability. You answer a series of YES/NO questions and then your personality is identified. You could be either a neurotic extrovert, a neurotic introvert, a stable introvert or an unstable extrovert

2) The Eysenck Personality Questionnaire (EPQ) This measures extroversion, introversion and neuroticism as well as psychoticism.

Most people score low on this trait, high scorers tend to be aggressive, cruel and lacking in feelings. The three dimensions are not linked.

What is Anti-Social Personality Disorder?

APD = a condition in which the individual does not use socially acceptable behaviour or consider the rights of others.

Features of APD:

It affects 3% of males, 1% of females and 75% of the prison population

Characteristics of APD – The DSM manual says you need to suffer from 3 of the following to be diagnosed with APD and although you may show symptoms at an earlier age, you cannot be diagnosed until age 18. The symptoms tend to get better as a person gets older.

Not following norms and laws of society Aggressive – involved in fights and assaults Irresponsible – failure to hold down a job or pay back money Lacking remorse for actions – can lie or steal and feel no guilt

Causes of APD

Biological:

Problems with the amygdala and prefrontal cortex are believed to cause APD

The amygdala responds to fear and emotion. It is believed that people with APD have a faulty amygdala so do not recognise fear and emotion in others and therefore can cause them harm more easily than others.

The prefrontal cortex is that part of the brain to do with learning right and wrong and makes us feel guilt if we do something wrong. It is believed that people with APD have less grey matter in this part of the brain, meaning that they have lower morals and do not feel guilt for doing things wrong.

Situational:

APD is caused by the environment a child is brought up in. Risk factors include:

o Socioeconomic factors (low income and poor housing)o Poor parentingo Poor school achievement

Studies of APD

Cause: Biological Situational/EnvironmentalName: Raine et al (2000) Farrington (1995)Aim: To investigate whether problems in

the prefrontal cortex causes APDTo study offending and anti-social behaviour in males from childhood to age 50

Method: MRI scans given to 21 men with APD and 34 healthy male volunteers

Longitudinal study of 411 males from a poor part of London. Parents and teachers were interviewed. Any crimes committed by them or family members were recorded.

Results: APD group had 11% less prefrontal grey matter than the control group

41% of the males committed at least one offence. Biggest risk factors were criminal behaviour in the family, low school achievement, poverty and poor parenting.

Conclusion: APD is caused by a reduction is prefrontal grey matter.

The situation a child is raised in causes anti-social behaviour

Evaluation: It supports the biological explanation of APD

Cannot generalise to women or non-volunteers

The brain is complex and APD may also be caused by problems in other areas of the brain

It supports the situational explanation of APD

It ignores biological factors involved in APD, such as brain damage

The people who were interviewed may have given socially desirable answers

Implications and applications of research into APD

Implications Applications There is a debate about what causes APD –

some research supports a biological link and other research supports a situational link