We Are Our Brains

While the adolescent PFC is still immature, parents have to be responsible for a child’s planning, organization, moral framework, and limits. These functions are gradually taken over by the slowly maturing PFC.

There was a time when an obscure mix of arguments bearing on eugenics, punishment, the protection of society, and the repression of homosexuality led to the castration of pedosexuals in the Netherlands. Between 1938 and 1968, at least four hundred sex offenders were “voluntarily” castrated. This practice wasn’t laid down by law. These were offenders detained under a hospital order who were given the choice of life imprisonment or castration. They had to submit a standard letter to the minister of justice, the text of which ran, “May I humbly crave Your Excellency’s permission to be castrated?” Up to 1950, 80 percent of the castrated men were pedosexuals, a situation complicated by the high legal age of sexual consent (sixteen). In Germany, the hypothalami of pedophiles were surgically lesioned in the hope that this would change their sexual orientation. These brain operations were never scientifically documented.

ll the data indicates that gender problems arise in the womb. Tiny variations in genes associated with the effect of hormones on brain development have been found to increase the likelihood of transsexuality. It can also be increased by abnormal fetal hormone levels or by medication taken during pregnancy that inhibits the breakdown of sex hormones. The differentiation of our sex organs takes place in the first months of pregnancy, while the sexual differentiation of the brain occurs in the second half of pregnancy. Since these two processes take place at different times, the theory is that in the case of transsexuality, they have been influenced independently of one another. If this is the case, one would expect to find female structures in the brains of MtF transsexuals and vice versa in the case of FtM transsexuals.

Homosexual behavior has now been observed in around 1,500 animal species, from insects to mammals. The male penguin couple Roy and Silo in New York’s Central Park Zoo are a famous example. They copulated, built a nest together, took care of an egg that a kindly keeper gave them (hatching it out after thirty-four days), and together looked after the baby. If a female rat develops alongside a male rat in the womb, thus being exposed to more testosterone during early development, it will mount other female rats. Two percent of oystercatchers, a monogamous bird species, form a trio of two females and a male, after which all three guard the same nest. A trio of this kind produces more offspring than a conventional pair, because they are better able to look after and protect the nest.

It is curious that a genetic predisposition for homosexuality should persist in populations over the course of evolution, given that this group reproduces so much less. One explanation for why homosexuality persists is that the involved genes don’t just increase the likelihood of homosexuality but also promote fertility in the rest of the family. Heterosexual individuals with the same genes produce a larger than average number of offspring, causing the genes to remain in circulation.

ll the research indicates that our sexual orientation is programmed in the brain before birth, determining it for the rest of our lives

Alfred Kinsey didn’t attract any notice when he published his doctoral thesis on gall wasps. But in 1948, when he produced the report Sexual Behavior in the Human Male and then, five years later, Sexual Behavior in the Human Female, he became a celebrity. He devised the “Kinsey scale,” which went from 0 to 6, 0 signifying exclusively heterosexual and 6 exclusively homosexual. Being bisexual, he himself would have been classified as a “Kinsey 3.”
A person’s position on the scale is determined in the womb by his or her genetic background and the effects of hormones and other substances on the developing brain. Studies of twins and families show that sexual orientation is 50 percent genetically determined, but the genes in question haven’t yet been identified.

Brain cells are created with incredible rapidity in the womb and shortly after birth, and this process continues, somewhat more slowly, until around the fourth year of life. Brain maturation goes on much longer; in the case of the prefrontal cortex, it continues right up to the age of twenty-five.

When a mother is fearful during pregnancy, she can permanently activate her baby’s stress axis, thus increasing the risk of phobia, impulsiveness, ADHD, and depression later in life.

A child’s first language isn’t determined by its genetic background, only by the surroundings in which it grows up during that critical period of language acquisition. Not only does acquiring language have a very marked effect on the brain, it’s also crucial to many other aspects of a child’s development. In 1211, the Holy Roman Emperor Frederick II of Germany, Italy, Burgundy, and Sicily tried to establish what language God spoke to Adam and Eve. He believed that children would spontaneously speak it if they were not exposed to other languages and set up a rigorous experiment in which dozens of children were brought up by nurses ordered never to speak to them. However, his hopes were met with disappointment. The children couldn’t speak at all, and they all died at a young age.