we're just seeing the reverse of darwinism--people who are least fit to reproduce (idiots with no intelligence, physically inferior, can't support themselves) are having the most offspring, and their offspring are otherwise healthy and live long enough to reproduce.
we have a rule in the trauma world--if you do not have a high school education, are unemployed, have more tattoos than teeth, and do not know where both your parents live, then you are virtually indestructible--you will survive stabbings, shootings, being hit by a semi, etc. etc.