Twin Personalities

Ben Thomas compiles evidence that variances in young adulthood, early childhood, and even in utero nutrition set in motion the distinct personalities of genetically identical twins:

In short, Kempermann says, “Experience matters. Genes are clearly critically important – but even given identical genes and an identical environment, different experiences lead to different personalities, and to the individualization of the brain.” It’s a comforting thought, in its way: Even if DNA encodes the basic recipe for your personality; even if epigenetic changes started cooking up the ingredients months before you were born, your personal choices and experiences also define how those ingredients come together – and, to a certain extent, what sorts of recipes you pass on to your children.

It doesn’t seem reasonable, then, to claim that individuality is somehow innate at the moment of conception; or at any single point in anyone’s development. Rather, it’s a process – a series of changes that begin at the molecular level and add up over time, spurred on by the unbroken flow of unique accidents, triumphs, letdowns and challenges each individual faces every day, from pre-conscious prenatal development to the last gasping breaths of old age.