"Humans are selfish and vile" != "There are humans that are selfish and vile".

It appears that when push comes to shove, humans on average return to selfish and vile behavior.

There have been accounts of divers, for example, losing their oxygen source and then in survival mode killing their best friend trying to obtain life-giving breathe.

This type of behavior seems to be the norm.

There are also many horrific accounts during hurricane Katrina along these lines. Some of these were covered by NPR.

It goes to show that if shit ever really hit the fan, you might have to be prepared for zombie-like behavior.

The parenting motto is “make it easy to be good”. For kids at least this starts with sufficient healthy foods, enough sleep, and some autonomy over ones own actions.

Some call this idea "The Fundamental Attribution Error".