Why do humans behave like animals?

This sounds like a RHETORICAL question, but I'll give it a try, and please keep in mind this is a personal opinion.

It's a firm belief of mine that ONE out of every FIVE adults alive today has some form of. MEMTAL HEALIH issue. I can't say if it's because of Hormones or a chemical imbalance passed on through Genes, or it just might be that some folks can't take the competition of today's fast paced lifestyles.