Psychopathology, brain development, genetics, and the effects of family life on human development

How profoundly does our early environment affect us? Neuroscientist James Fallon says,

I found out that I happened to have a series of genetic alleles, "warrior genes," that had to do with serotonin and were thought to be at risk for aggression, violence, and low emotional and interpersonal empathy—if you're raised in an abusive environment. But if you're raised in a very positive environment, that can have the effect of offsetting the negative effects of some of the other genes.

Fallon tells an interviewer for the Atlantic,

The jump from being a "prosocial" psychopath or somebody on the edge who doesn't act out violently, to someone who really is a real, criminal predator is not clear. For me, I think I was protected because I was brought up in an upper-middle-class, educated environment with very supportive men and women in my family. So there may be a mass convergence of genetics and environment over a long period of time. But what would happen if I lost my family or lost my job; what would I then become? That's the test.

There are some critical periods in human development. For the epigenome, the first moment is the moment of conception. That is when the genetics are very vulnerable to methylation and, therefore, the effects of a harsh environment: the mother under stress, the mother taking drugs, alcohol, and things like that. The second greatest susceptibility is the moment of birth and, of course, there are the third and fourth trimesters. After that, there is a slow sort of susceptibility curve that goes down.

The first two years of life are critical if you overlap them with the emergence of what are called complex adaptive behaviors. When children are born they have some natural kinds of genetic programming. For example, a kid will show certain kinds of fear—of certain people, then of strangers, then it’s acceptance of people—that’s complex-adaptive behavior at work in social interactions. But even laughing, and smiling, and making raspberry sounds are all complex-adaptive behaviors, and they will emerge automatically. You don't need to be taught these things.

One idea is that over the first three years there are 350 very early complex adaptive behaviors that go in sequence, but if somehow you’re interrupted with a stressor, it will affect that particular behavior that’s emerging or just about to emerge. It could be at a year and half, 3 months, or 12 months. After that, the effects of environment really start to drop; by the time you start hitting puberty, you kind of get locked in. And during puberty your frontal lobe system does a switch.

There are some critical periods in human development. For the epigenome, the first moment is the moment of conception. That is when the genetics are very vulnerable to methylation and, therefore, the effects of a harsh environment: the mother under stress, the mother taking drugs, alcohol, and things like that. The second greatest susceptibility is the moment of birth and, of course, there are the third and fourth trimesters. After that, there is a slow sort of susceptibility curve that goes down.

The first two years of life are critical if you overlap them with the emergence of what are called complex adaptive behaviors. When children are born they have some natural kinds of genetic programming. For example, a kid will show certain kinds of fear—of certain people, then of strangers, then it’s acceptance of people—that’s complex-adaptive behavior at work in social interactions. But even laughing, and smiling, and making raspberry sounds are all complex-adaptive behaviors, and they will emerge automatically. You don't need to be taught these things.

One idea is that over the first three years there are 350 very early complex adaptive behaviors that go in sequence, but if somehow you’re interrupted with a stressor, it will affect that particular behavior that’s emerging or just about to emerge. It could be at a year and half, 3 months, or 12 months. After that, the effects of environment really start to drop; by the time you start hitting puberty, you kind of get locked in. And during puberty your frontal lobe system does a switch.

Then, there’s a switch that occurs late in adolescence. For some people it could be 17, 18, 19, or 20-years-old. What happens is that the upper part of the brain, the frontal lobe and its connections, start to mature. That's a critical time because that’s usually when you see schizophrenia, some forms of depression, and those major psychiatric disorders emerge. For personality disorders it’s not really known when they will emerge because it’s very understudied. People will say, you can’t do anything about it, it’s locked in and there seems to be almost no treatment. Whereas, for things like depression, bipolar, schizophrenia, anxiety disorders, you can do something about it. There are drugs, or things you can do with brain stimulation and talk therapy, so that's where Big Pharma and the whole industry goes.

You start to really see personality disorders emerge around puberty, but for some children who might be primary psychopaths—that is, they have all the genes and their brain sort of set in the third trimester—this can start emerging very early, around 2 or 3-years-old. That is why we have to have more trained eyes—because that is where this becomes important for society.

A primary psychopath won't necessarily be dangerous, but if we can see that in a kid, we can tell parents to look for certain kinds of behavior. And if those behaviors emerge, we can safely discuss, protecting the privacy of that family and of the kid, how to have the child interact with a nurse practitioner or a trained professional. At that point, we can say: Make sure this kid is never bullied in school; keep them away from street violence, on and on.

Different, but complementary!

There is a fascinating post here on the differences in the male and female brains. Here is a graphic from the article.

Steve Conner writes at The Independent,

Researchers found that many of the connections in a typical male brain run between the front and the back of the same side of the brain, whereas in women the connections are more likely to run from side to side between the left and right hemispheres of the brain.

This difference in the way the nerve connections in the brain are “hardwired” occurs during adolescence when many of the secondary sexual characteristics such as facial hair in men and breasts in women develop under the influence of sex hormones, the study found.

“These maps show us a stark difference - and complementarity - in the architecture of the human brain that helps to provide a potential neural basis as to why men excel at certain tasks, and women at others,” said Ragini Verma, professor of radiology at the University of Pennsylvania in Philadelphia.

Conner writes,

The only part of the brain where right-left connectivity was greater in men than in women was in the cerebellum, an evolutionary ancient part of the brain that is linked with motor control.

Men tend to outperform women involving spatial tasks and motor skills - such as map reading - while women tend to better in memory tests, such as remembering words and faces, and social cognition tests, which try to measure empathy and “emotional intelligence”.

A separate study published last month found that the genes expressed in the human brain did so differently in men and women. Post-mortem tests on the brain and spinal cord of 100 individuals showed significant genetic differences between the sexes, which could account for the observed gender differences in neurological disorders, such as autism, according to scientists from University College London.

For instance, one theory of autism, which is affects about five times as many boys as girls, is that it is a manifestation of the “extreme male brain”, which is denoted by a failure to be able to show empathy towards others.