Scientific discussion of personality heritability and neurobiology, no actionable leads

behavioral inhibition and anxiety, behavioral flexibility, narcissism, deviant motor activity levels, novelty seeking, harm avoidance and reward dependence. These studies were conducted by R.R. Crowe, J.F. Rosenbaum, A. Methany, and J.L Robinson and indicated familial congruity of these characteristics among first and second degree relatives in the range of 40-50%. This level of heritability in genetically unrelated family members was found to be less than 20%. Low entropy fixations of personality can also evolve developmentally. Experiments in young animals have shown that stress-induced high levels of adrenal hormones exaggerate the normal developmental process of trimming back unused neural connections, called pruning, the normally complexly over-grown sprouting pathways. The pruning actions of the pituitary-adrenal stress hormones come to dominate sprouting actions of neural growth factors and their protection of neuronal axonal branching and connections during development. The research program of Bruce McEwan of Rockefeller University and others document nerve cell loss resulting from the neurohormonal concomitants of stress. This reduction in neuronal connectivity and neuronal cell content has been conjectured to contribute to the pathological simplification of neuronal projections and neural network complexity, reducing information processing capabilities. The still intact machinery underlying the global patterns of neurological activity, such as those that underlie personality styles, is arranged around these pruned, unoccupiable holes of lost brain possibility. If this range of potential behavior is extremely reduced, the behavioral syndrome is often called a personality disorder. Those that have one are the predictable Johnny one notes of response to perturbation: thrash out, lie without reason, get drunk, binge on promiscuity, steal unneeded things from department stores, or withdraw into interpersonal isolation. A more abstract and quantifiable way of representing the pathological simplification-induced emergence of low entropy, stereotypical personality style is inscribed on the head stone of the post-suicidal grave of Ludwig Boltzmann. This father of modern statistical physics expressed the idea in the form of a transformation: the (maximal) entropy, S, of a system is the logarithm of the number,Q, of its available ways of being, (i.e., S = log ). That is, one way a 30 HOUSE_OVERSIGHT_013530