

Biology is not fully reducible to genetics, and behavior is not fully reducible to biology. I’ve found myself using that adage more often in conversation, so I thought perhaps it would be helpful to mention and unpack here. As far as I know, that particular phrasing is mine, but the sentiment I believe is fairly representative of what biologists think. While there may be a popular expectation finding genes for every personality trait, the reality is that genes can only have so much influence. That should be apparent even from the raw numbers. We have roughly 25,000 genes and 100 trillion neural connections; so few genes cannot possibly fully specify how our brains are wired, especially considering everything else those genes also have to do. Even when genes get a label like the “warrior gene” the most we can about it is that it is associated with a higher tendency toward certain behaviors, rather than being fully deterministic.
[Read more…] about Science Corner: The Skinny on Genes