12. Human Brains Have Shrunk
Oftentimes, when we call someone or another species unintelligent, we typically wonder if their brain is merely smaller than it should be. Words like “pea brain” are thrown around as insults even! Yet the funniest part of this is that most human brains are the same size and all of us have smaller brains than humans used to have. Seriously, our brains have been slowly shrinking for more than 20,000 years thus far.
The total change in that time is reportedly the size of a tennis ball in adult males according to scientists. This does not mean we’re getting dumber, however, far from it! The standing theory is that humans rely on certain structures of the brain to help us get by, so the extra space is not as needed as it used to be. This could also result in smaller heads over time too. Heck, even animals like dogs and cats have experienced this same thing.