This pattern isn’t limited to mass shootings. While those between the ages of 14 and 24 constituted a little more than 16% of the population between 1980 and 2008, they were responsible for over 48% of the murders. Overall, those 18 to 24 consistently had the highest offending rate over the 28-year period. And the overwhelming majority of those responsible for homicides were male. //

The rate of suicide attempts is also highest between ages 14 and 21.

There are good reasons for these statistics: The frontal lobe and other parts of the brain responsible for impulse and emotional control and judgment do not fully mature until roughly age 25 or 26. Additionally, 75% of people who develop psychiatric disorders will do so by 24, while the peak onset of psychotic disorders in men is just under 25. //

Auto-insurance rates are higher for drivers under 25, because, statistically, they are responsible for more accidents than any other group. Similarly, most car-rental agencies either don’t rent to people under 25 or charge them a premium. Even Airbnb enacted restrictions on rentals for those under 25 to make it harder to throw potentially dangerous and destructive house parties.