To what extent does human behavior is affected by biology? A summary of an article.

Robert Sapolsky, a professor of biological sciences and neurology at Stanford University, starts his article with an example of strikingly different changes in lives of two people with the same gene mutation, frontotemporal dementia. Illustrating the progress of neuroscience, he lists what the scientists know already: how neurons connect and die, how our brains decode senses and coordinate muscles, how genes interact with the environment, how abnormal gene increases the risk of a dysfunction but only under specific conditions, how environment can shape our brains, and even how we learn.

A brain trauma can cause atrophy of neurons in one brain region and their expansion in another, changing our perceptions of and reactions.

Sapolsky names more studies, suggesting that to the large extent we are products of our brains.

Men and women differ in their number of neurons, and transsexuals do not have the number of neurons typical of their birth gender, regardless how people behave or whether they had hormonal treatment, suggesting they do not have bodies matching to their chromosomes, genitals, hormones, etc. (Frank Kruijver)

Conditions like obsessive-compulsive disorder, borderline personality, avoidant personality, religiosity from temporal lobe epilepsy, can be explained with the underlying neuroscience. Such insights matter because they should influence our educational, medical, and justice systems.

Neuroscience will become a descriptor for all of us, because likely we all have abnormalities. Eventually, we will be able to repair these problems, which might introduce societal inequalities and excesses. On the bright side, the hard divide between health and disease will disappear in medical continua, which calls for compassion and tolerance.

Sapolsky does not specify to what extent our behavior is affected by biology, he leaves the "nature over nurture" question open in terms of proportion and frequency. But he offers evidence to its significance we cannot anymore ignore in the process of building our societies.