Gender Differences You’ve Likely Never Heard About
Fourteen neuroscientists from the University of California, the University of Michigan, and Stanford University analyzed thirty samples of human brain tissue taken from different parts of the brains of a number of different people. This was a blind test; the neurosurgeons did not know anything about the identify of the person from whom each tissue sample was derived. Without exception, these neuroscientists were able to determine the sex of the individual from whom the sample was derived (1).
Why is that so?
It turns out, the brain is a sexual organ. It is paramount in determining sexual identity (not the physical genitals, but the metaphysical sexual identity). From birth, human brains are physically differentiated based on a person’s sex, function differently based on sex, and produce different results based on sex.
This idea was introduced to me by Nora Hale . Here are a list of gender differences between males and females that are hard-wired into our physical bodies – not just our brains – and affect how our bodies work. Some of them might surprise you.
I had a fun time discussing these gender differences with our two boys – even though some of the concepts were a bit over their heads. The main idea to get across is that God created males and females to be distinct from each other, but in a way that makes us interdependent. As you discuss the differences, see if your kids can identify the distinctions (that should be easy!) and why God might have made males and females to be different in order to be interdependent.
The brain is sexually identifiable
Males have X and Y chromosomes inside every cell in their bodies. The Y chromosome is responsible for releasing a flood of testosterone and coats brain tissue with a distinct expression of proteins. Females only have X chromosomes inside the cells in their bodies. This creates a different protein expression in the brain tissue than that in the male brain. This is why the neuroscientists noted above had a 100% accuracy rate in identifying the sex of the person based on their brain tissue alone.
Male and female brains are physically different
If you look at your brain “top down” it is divided into two halves – or hemispheres – much like a walnut or a pecan appears divided into two halves. We often associate each half with particular functions – but this isn’t quite accurate. Male brains have more connections within each of the two separate hemispheres. Female brains are more interconnected between hemispheres themselves. Females do not have the strict right verbal left spatial divide in their brains like males do.
Structural differences dictate how the brain operates
There is a reason that men can more easily compartmentalize their thinking – laying aside problems at home when at work, and vice versa, and women can’t. The physical structure of the male brain allows them to do this. Females have what is sometimes called “spaghetti” thinking – females cannot set aside one problem to focus on another – they tend to have more subconscious thinking and mixing of their thoughts than men. However, a female’s brain structure also makes her better at multi-tasking.
Brain structure affects other areas of thinking as well. Studies have shown that;
- Males and females use different parts of the brain to solve mathematical problems (2);
- Males will suffer far more verbal IQ loss after a stroke in their right brain hemisphere than females because their brain functions are more compartmentalized (3);
- Males and females use different areas of the brain for navigation (4);
- Males and females process negative emotions in different areas of the brain (3, 4); and
- Males’ brain size is a function of IQ (a higher IQ generates a physically bigger brain) where as womens’ brains do not alter in size based on IQ (3).
Male and female eyes are structurally and functionally different
The X and Y chromosome differences between males and females affect eye retina. Eye retinas are full of receptors for sex hormones. The male retina is much thicker than the female retina because its mostly made of larger, thicker M (magnocellular) ganglion cells while female retina is mostly made of the smaller, thinner P (parvocellular) ganglion cells. There are no exceptions or overlaps to this between men and women.
The male’s M ganglion cells are programmed for movement (location, speed) and direction – they are little motion detectors that are spread out over the entire visual fields to track where something has come from and where it is going. It sends this information to an area of the cerebral cortex tasked with spatial relationships and object motion called the posterior parietal cortex.
The female’s P ganglion cells are concentrated in the center of the field of vision and compile information on texture and colour. They send this information through a completely different set of wiring to a different part of the cerebral cortex (the inferior temporal cortex) that analyzes texture and colour.
These differences make females better at tasks involving discrimination and intuition and males better at tasks involving direction, speed, and location. As a result, males have a physical advantage for visual and spatial perception; females have a physical advantage for social awareness and intuition. (3)
Who is better?
I’m not sure why, but these discussions about gender differences often end up with someone wondering “Who is better, males or females?” Why do we ask this question? Do differences have to make one sex better than the other? Sax (3)argues that this question is about as relevant as arguing which utensil is better: a knife or a fork. What you need to ask is: “Better for what?” Sometimes there isn’t a ‘better’ (like the different ways males and females process math), sometimes there is (like how males can discern location, distance, and speed more readily than females). The question shouldn’t be ‘better’, but ‘how does how I’m created fit in with why I’m created’. This is another great discussion to have with your kids after reviewing some of this material with them.
Which of the gender differences in this list surprised you the most?
(3) Sax, L. (2007) Why Gender Matters. Potter/TenSpeed/Harmony