ABSTRACT

One strand of evidence which would support the stability of adult personality would be its inheritability. This has been most convincingly investigated by comparing the scores of identical twins reared apart from each other. A second strand would be a relationship between scores for intelligence and the Big Five personality dimensions and variations in the structure and/or functioning of the brain. The third stream of evidence is the test-retest statistics for intelligence and the Big Five factors. With regard to the Big Five personality traits, the authors of the NEO series of personality questionnaires concluded their review of Personality in Adulthood with the words study after study has shown that, aside from small declines in Neuroticism, Extraversion, and Openness, there is neither growth nor decline in adult personality after the age of 30. One of the most exciting prospects for changing personality was outlined in a BBC2 Horizon programme entitled 'The truth about personality.