Previously: https://news.ycombinator.com/item?id=46045661

No no no. Here is the age thing:

At some point between the ages 17 to 24 the prefrontal cortex develops a circuit directly to the limbic system. The result is an aggression regulator that did not exist prior. The age thing was discovered by looking at violent crime rates correlated against age and affirmed by physiological research of the brain.

That’s it.