What do you think?
Do you have relevant anecdotes?
edit: To elaborate, I think people should be checked for mental stability, and these people should have a set of values that not extremely deviant from what is lawful.
Anecdotes? Bipolar women, with no husband, who start doing crack after their baby is born. The daughter becomes a sex worker to fund her mother's rehab.
edit #2: Since I have no answers, incompetent people should be instructed to only have butt sex.