Prompted by a piece on Robert Paterson’s site, featuring a lecture by Robert Sapolsky, I revisited an interview with Sapolsky at Edge. (By the way if you want an education on the impact of stress on the immune system, put aside some time to watch the lecture – it’s gold dust.) A bit in the earlier interview than didn’t really register first time round – I was more interested in the cool baboons who opted out of being Alpha males – was this bit about the relationship between the development of morality and the frontal cortex:
“Moral development is very heavily built around a part of the brain I used to ignore because you don’t find much of it in a lab rat: the frontal cortex. The frontal cortex is an incredibly interesting part of the brain, since it’s the nearest thing we’ve got to a super-ego. It’s the part of the brain that keeps us from belching loudly during the wedding ceremony, or telling somebody exactly what we think of the meal they made, or being a serial murderer. It’s the part of the brain that controls impulsivity, that accepts the postponement of gratification, that does constraint and anticipation, and that makes you work hard because you will get into an amazing nursing home one day if you just keep pushing hard enough. It’s all about this very human realm of holding off for later.
The most amazing thing is that there is a dogma of neural development. The dogma is that by the time you’re a couple of years old, you have your maximal number of neurons, and all of them are wired up and functioning. But it turns out that we make new neurons throughout life, and parts of the brain don’t come fully on line until later. And, amazingly, the last area to do so is the frontal cortex, not until around age 30 or so. It’s the last part of the brain to develop, and thus it’s the part whose development is most subject to experience, environment, reinforcement, and the social world around you. That is incredibly interesting.
To put this in personal terms, my six-year-old might do something appallingly horrible and selfish and age appropriate to one of my three-year-old’s toys. As a parent you swoop in and say, ‘This is not acceptable and you cannot do that.’ But just as I (or my wife who is a clinical nurse-psychologist, and so, pathetically, we actually speak like this at home) am saying this, the other will say, ‘He can’t help it; he doesn’t have a frontal cortex yet,’ to which the first inevitably responds, ‘But how else is he going to get one?'”