The Ecology of Humans (28) The Brain by Gender

The Brain by Gender

Any difference in the structure or activation of male and female brains is indisputably biological. However, the assumption that such differences are also innate or
hardwired” is invalid, given all we’ve learned about the plasticity, or malleability of the brain. Simply put, experiences change our brains. ~ American neurobiologist Lise Eliot

The differences in anatomy between the sexes reach into the brain. There are ~100 gender distinctions in human brains. (Note that the gender generalizations that follow are exactly that: statistical typifications. Skill levels are always individual.)

Befitting the slight sexual dimorphism of humans, male brains are 10% larger than females: mostly to handle the greater musculature, not deeper thinking.

Female brains mature faster than those of males. Girls start talking before boys.

The myelination of cranial nerves is accomplished in female brains by the mid-teenage years. This process completes a year or 2 later in boys.

Myelin coating improves behavior regulation via glia taking control of nerve cells. Myelination exhibits a crucial role in inhibiting inappropriate behaviors and choosing actions to meet goals.

Generally, the halfway point of brain maturation is met in girls by age 11. Boys do not reach this point until 15.

Differences in the hypothalamus and amygdala emerge early in life. Women have a larger hypothalamus, affording better emotive memory. Meanwhile, men have a larger amygdala for faster stress response.

When stressed, males tend toward addressing the source: either fight-or-flight. In contrast, females turn to others for support.

Literacy does not come as easy for boys, who tend to have more problems learning to read, especially if socially disadvantaged or in large families.

The planum temporale – a cortical area involved with language fluency – is larger in women than men. The planum temporale is one of the most asymmetric regions in the brain. Its size in the left hemisphere – where language processing predominates – is up to 10 times larger than the right.

While males mostly process language in the left hemisphere, females have active verbal centers on both sides of the brain.

Women use more words when describing emotive experiences and show greater interest in sharing such. Men tend to briefly analyze emotional memories before moving on to a different task.

The female brain has greater blood flow in the cingulate gyrus, which lies just above the corpus callosum. The cingulate gyrus is involved in forming and processing emotions.

A discrepancy in empathy between genders emerges in infancy and persists throughout development, though the gap between adult women and men is greater than between girls and boys owing to cultural indoctrination. This consistency between the sexes suggests an innate basis for empathy in the mind-brain.

Men are better at tasks that involve imagining spatial relations, such as determining navigation paths. Males also have a decided edge in mathematical reasoning ability.

In social skills, perceptual speed, and fine motor skills, males are the weaker sex. Topping this cake is the fact that men have a lower pain threshold than women. In sum, women are smarter and tougher.

While sex-related mind-brain differences do matter, they do not fully explain behavioral divergences or cognitive abilities. Hormones play a large role, as does personality and life experience.

The straight gyrus is a narrow strip running along the midline on the undersurface of the frontal lobe. It appears involved in interpersonal awareness and social cognition.

Women generally a larger straight gyrus: by about 10%, which makes sense when considering that mothers are the primary parent. But the picture is more complex than that. Men or women with a more feminine personality have a larger straight gyrus than those that are more masculine. This indicates that hormones are influential.