Brains in a haystack

An essay by Gary Marcus, in the new online science magazine, Nautilus: “Where uniqueness lies”.

In short, humans may live very differently than chimpanzees, but the structural plans of our biology necessarily can represent only modest tinkerings to the genetic material that we inherited from our last common ancestors. Language, regardless of how it is instantiated in our brain, represents a comparatively tiny cognitive enhancement relative to the mental machinery we inherited from our last common ancestor. The same is true for the underlying biology of each of our cognitive innovations. If it seems like scientists trying to find the basis of human uniqueness in the brain are looking for a neural needle in a haystack, its because they are. Whatever makes us different is built on the bedrock of a billion years of common ancestry.

A lot of what’s interesting about humans is because we reuse the ancient systems of our brains in new ways. Technology and culture both help us to exploit systems shared much more broadly among animals. This greatly complicates our attempts to show what is really different about the biology of the human lineage, because shallow differences based on recent behavioral innovations abound.