Tourette's syndrome is a problem with the nervous system that causes people to make sudden movements or sounds, called tics, that they can't control. For example, someone with Tourette's might blink or clear their throat over and over again. Some people may blurt out words they don't intend to say.
Treatments can control tics, but some people don’t need any unless their symptoms really bother them.
About 100,000 Americans have full-blown Tourette's syndrome, but more people have a milder form...
While some brain features are more common in one sex than the other, and some are typically found in both, most people have a unique mix.
Research has found some key differences that could explain why we expect males and females to think and behave in characteristic ways.
But even if the physical brain doesn't change, how it works can.
Most Brains Are Both
A 2015 study at Tel Aviv University used an interesting and very thorough approach to compare the structure of male and female brains. Researchers looked at MRI scans of more than 1,400 people.
First, they measured the amount and location of gray matter (sometimes called "thinking matter") in 116 parts of the brain to find out which areas had the biggest sex differences. Next, the team scored these areas on each scan as either falling into the "female-end" zone, the "male-end" zone, or somewhere in the middle.
It turned out that maybe 6 in every 100 of the brains they studied were consistently a single sex. Many others had a patchwork quilt of masculine and feminine features that varied widely from person to person.
To check their findings, the team used similar methods to analyze more than 5,500 people's personality traits and behavior. While some activities were more common in women (including scrapbooking, chatting on the phone, and keeping in touch with mom) and others in men (such as golfing, playing video games, and gambling), 98% of those studied didn't fit a clear-cut gender profile.
Overall, the findings suggest that "human brains do not belong to one of two distinct categories."
'Brain Road Maps' Reveal Differences
While the MRI research mainly focused on brain structures, another scientist has been exploring the nerve pathways that link them, like a highway system for the brain's traffic.
We know that hormones influence brain development in the womb, yet before age 13, boys' and girls' mental circuitry appears similar. During puberty, hormones may again have a powerful effect and contribute to rewriting the teen brain.