Thomas, Chess and Birch 1977

Aim - To test if ways of responding to an environment are stable throughout life.

Method - 133 children were studied and observed for behaviours in the first 25 years of their lives. Their parents were also interviewed

Results - They found that the children fitted into one of three categories: easy, difficult or slow to warm up. The type of the child was stable throughout their life.

Conclusion - Temperament is innate as the children responded to the environment in the same way throughout their lives.

Evaluation - Longitudinal Study - More evidence to support claims
- All the children were from middle-class New York families so perhaps the results can't be generalised
- The parents may be biased or give false information in interviews

Buss and Plomin 1984

Aim - To test the idea that temperament is innate

Method - 228 DZ and 172 MZ twins were studied (observed and parents interviewed). They then scored the children on three scales: emotionality, sociability and activity

Results - They found that MZ twins' scores had closer correlation than DZ twins' scores

Conclusion - Temperament has a genetic basis

Evaluation - MZ twins may've had a more similar upbringing than DZ twins which would explain the closer correlation
- Scoring based on such scales is highly subjective and unreliable
- Cannot be generalised to whole population as only twins were researched

Eysenck 1947

Aim - To investigate the personalities of 700 servicemen

Method - Eysenck gave servicemen a questionnaire which he then analysed using a method known as factor analysis

Results - Eysenck identified two scales of personality: extroversion-introversion and neuroticism-stability

Conclusion - Everyone can be placed on the two scales

Evaluation - He only used a limited sample for his research so had he used more his results would've had more evidence to back them up
- He used questionnaires. The answers given could've be false or reflect moods at the time rather than actual facts
- He only used male servicemen. This means perhaps his results shouldn't be generalised to the whole population

Raine et al 2000

Aim - To test the theory that APD is caused by anomalies in the brain

Method - 21 men with APD and 34 men without APD were given MRI scans of their brains

Results - Men with APD had 11% reduction in prefrontal grey matter compared with the men without APD

Conclusion - APD is caused by a reduction in the brain's grey matter

Evaluation - He only used men so the results can't be generalised to women
- He only used limited samples of both groups. Had he used more he may've found more or contrasting evidence
- It is unclear whether the reduction caused APD or APD caused the reduction

Farrington 1995

Aim - To investigate the development of offending and APD in males from childhood to the age of 50

Method - A longitudinal study was carried out with 411 inner-city males, followed from 8 to 50. Their parents were also interviewed and the police were contacted about whether any of the participants' families had any criminal records

Results - 41% of males were convicted of at least one offence between the ages of 10 and 50. Factors responsible included criminal behaviour in the family, poverty, poor parenting and low school achievement

Conclusion - Situational factors lead to a development of APD

Evaluation - As parents were interviewed, biased or exaggerated answers may've been given thus affecting the conclusions's reliability
- This wasn't a controlled experiment so other factors like biology weren't considered
- Only males were used so results shouldn't be generalised

	Created by pauldearden over 10 years ago

a level Psychology Note on Personality Studies, created by pauldearden on 31/05/2014.