Unit one: Development of personality

Aim: To discover whether ways of responding to the environment remainstable throughout life.

Method: 133 children were studied from infancy (2-3 months) to early adulthood. This a longitudinal study. The children's behaviour was observed and their parents were interviewed at various intervals, they were asked about child's routine and reaction to change.

Results: They found tha children fell into 3 types: 'easy' (happy, flexible, regular) 'dfficult' (demanding, inflexible, cried alot) or 'slow to warm up' (didn't respind well to change or new experiences, but once adapted usually happy.

Conclusion: These ways of responding to the environment stayed with the children as they developed.Therefore temperment is innate (natural)

Evaluation: This study could be criticised for low population validity, this means the findings can not be generalised to other social classes. This is because the children studied were from middle-class families living in new york.

Aim: To test whether temperment is innate.

Method: 228 pairs of monozygotic twins and 172 pairs of dizygotic twins were studied at the age of 5 years. Their temperament was rated, 3 dimensions of behaviour were looked at: Emotionally (how strong the child's emotional response was), activity (how energetic the child was), sociability (how much the child wanted to be with other people. The scores for each pair were then compared.

Results: The monozgotic twins had more closely correlated scores than the dizygotic twins.

Conclusion: Temperament has a genetic basis.

Evaluation: This study supports the views that temperament is innate. This is because the monozygotic twins, who are genetically identical, were more similar in emotionality, activity and sociability than the dizygotic twins, who are only genetically similar.

Aim: To investigate whether temperament is due to biological differences.

Method: The reactions to new situation of 500 babies aged 4 months were studied. For the first minute the baby was placed in a seat with the caregiver nearby. For the next three minutes the caregiver moves out of view of the baby and the researcher showed the baby different toys.

Results: 20% of the babies showed distress by crying, vigorous movement of arms and legs and arching of the back (high reactive). 40% showed litle movement or emotion (low reactive). The rest were somewhere inbetween the two.

11 years later in a follow up study, there was still a difference in the way the two groups reacted to new situation; high reactves were shy and low reactives were calm.

Conclusion: These two temperaments are due to inherited differences in the way the brain responds.

Evaluation: This study can be criticised for low ecological validity, this means the findings can not be generalised to a real life setting. This is because the study took place in a cotrolled environment that would not have been familiar with the children, therefore they may have behaved differently due to demand characteristics.

Aim: To investigate the personality of 700 servicemen.

Method: Each soldier had to complete a questionnaire. Eysenck analysed the results using a statistical technique called factor analysis.

Results: It was identified that there are two dimensions of personality: Extroversion-Introversion and neuroticism-stability.

Conclusion: Everyone can be placed along these two dimensions of personality. Most people lie in the middle of the scale.

Evaluation: Personality questionnaies can be criticised for low in validity. This is when they do not measure what they intended. This is because people may show social disireability and lie in their answers. Further more, the mood a person is in could affect how they answer.

According to eysenck, personality describes these parts of our identity which are inherited and make up our thoughts and behaviours. He argues there are three main types:

• Extroversion: people who look for the outside world for entertainment.
• Introversion: people who content with their own company.
• Neuroticism: people who are highly emotional and show a quick intense reaction to fear.

There is also psychoticism which refers to a level of hostility and agressiveess.

EPI (Eysecks Personality Inventory) is used to measure mainly introversion and extroversion.

EPQ (Eysencks Personality Questionnaire) reffers to psychoticism.

Personality is measured on a scale between both of these.

Aim: To investigate the development of offending behaviour and antisocial behaviour in males.

Method: A longitudual study was carried out with 411 males. They all lived in a deprived inner-city area of London. They were first studied when they were 8 years old and followed up until they were 50 years old. Their parents and teachers were interviewed. Searches were carried out at the Criminal Records Office to discover if they, or any members of the family had been convicted of crime.

Results: 41% of the males were convicted of atleast one criminal offense between the ages of 10-50. The most important risk factors for offending were criminal behaviour in the family, low school achievement, poverty and poor parenting.

Conclusion: Situational factors lead to the development of anti-social behaviour.

Evaluation: This study can be criticised for low population validity. This is when the findings can not be generalised to a wider population in a varitey of settings. This is because the study was only done on males who live in a deprived part of London, therefore this study can not represent females or other areas of the country.

Practical implication: If APD has a situational cause, then reducing childhood problems should lower the risk of APD developing.

Aim: To investigate childhood risk factors that can be used to predict antisocial behaviour in adulthood.

Method: 225 twins who were diagnosed with childhood disorders were investigated and interviewed 10-25 years later.

Results: Childhood hyperactivity, leads to disorders, low IQ and reading problems. These were strong predictors of APD and criminality in adult life.

Conclusion: Disruptive behaviour in childhood can be used to predict APD in aduthood.

Evaluation: This study can be criticised for low population validity, this means thee findings cannot be applied to a wider population in a variety of settings. This is because this experiment was only done on twins, therefore it doesn't represent people that are not twins.

Practical implication: Identifying risk factors ffor APD can lead to some groups being overlooked. Children who have had a stable childhoodd can also develop APD.

Aim: To support the theory that adnormalities in the prefrontal cortex causes APD.

Method: MRI was used to study 21 men with APD and a control group 34 healthy men. The subjects were al volunteers.

Results: The APD group had an 11% reduction in the prefrontal grey matter compared wih the control group.

Conclusion: APD is caused by a reduction in the brains grey matter

Evaluation: This study can be criticised for low population validity, this means the ffindings cann not be generalised to different groups. This is because it only studied men participants meaning the results tell us little about APD in women.

Practical implication: If APD has a biological cause then it cannot be prevented.