To give a broad overview of an area that may be crucial to illuminate the genesis of personality disorders, I shall discuss the studies that, during the last decade, have tried to find genetic traces for personality traits that are both behaviourally consistent and biologically well rooted. Previous work using classical (familial or twin) methods had found substantial heritability estimates for several personality traits. It was thus unsurprising that genetic tracking methods impulsed research aimed at showing that temperamental traits contribute to personality scaffolding via neuroendocrine targets specified by particular genes. I’ll be discussing the outcome of some of these efforts and I’ll explore afterwards how other basic temperamental traits, rooted within biodevelopmental processes, do mediate enduring neurocognitive organization resulting in long-lasting behavioural styles. Finally I’ll outline new avenues for the neuropsychology of personality. My approach is deliberately selective, discussing relevant evidence rather than performing a systematic assessment of the field. For reasons of convenience and possible clinical relevance, I have selected some of the traits heralding sound biological foundations, although they are not necessarily prominent in the state-of-the-art dimensional ‘solutions’ for normal and abnormal temperaments.
PERINATAL OUTCOME OF SECOND BORN TWIN