Nature or nurture? Check your beliefs; sometimes, and I know it’s difficult to believe, ones beliefs need, at least, updating. In this case it’s important because of how it bears on the issue of how flexible humanity’s behavior can be expected to be in the face of environmental catastrophe. Are we fixed by out genes and therefore doomed, as some people assert? Or can we learn, or otherwise adjust our behavior in the face of urgent need? The article referred to here, is published in Aeon, a website that publishes science related essays on the Internet caused me, in discussion with some friends, to reappraise some previously firmly held opinions.
First, the article discusses heredity of learned behavior in mice (NOT in the species pictured here; it’s the only mouse picture I had). Give a mouse a sniff of almonds and an electric shock, and soon the mouse exhibits fear at the smell alone. The interesting part is that so do untrained second and third generation descendants! Learned behavior has been inherited! The article has a considerable discussion including:
“In his book On Human Nature (1978), the evolutionary biologist Edward O Wilson claimed that human culture is held on a genetic leash. The metaphor was contentious for two reasons. First, as we’ll see, it’s no less true that culture holds genes on a leash. Second, while there must be a genetic propensity for cultural learning, few cultural differences can be explained by underlying genetic differences.”
“In 2011, another extraordinary study reported that worms responded to exposure to a nasty virus by producing virus-silencing factors – chemicals that shut down the virus – but, remarkably, subsequent generations epigenetically inherited these chemicals via regulatory molecules (known as ‘small RNAs’).”
Second, the article considers what I’d previously understood as genetically controlled behavior; wrongly, as it turns out. “Among the most compelling data are studies that cross-fostered great tits and blue tits (The picture is a Mountain Chickadee, close, but no cigar). When raised by the other species, these birds shifted numerous aspects of their behavior towards the behavior of their foster parent (including the height in trees at which they foraged, their choice of prey, foraging method, calls and songs, and even their choice of mate). Everyone had assumed that the behavioural differences between these two species were genetic, but it turns out that many are cultural traditions.”
So, if both ‘science’, and worse, me. could be wrong about genetic control of behavior in these kinds of circumstances, where else are we wrong? I would say it’s best to not be too firm in our beliefs about the genetic fixity of human behavior!
The full article, an easy read, has much more in it than the three brief quotes above.