The Selfish Gene At Work

This makes sense, actually...

THE risk of suicide is two to three times higher among men with low intelligence, and poorly performing offspring of well-educated parents are at the greatest risk.

... if considered in light of the selfish gene.

(and yes, in this case it would be a combination of genes and culture, but for sake of argument, bear with me in the simplification here)

A gene that caused its host to destroy itself would help to ensure the survival of the species as a whole by pruning out an unproductive member, but this would only be to the gene's reproductive advantage if the gene were almost completely widespread. Which explains why we all feel like throwing in the towel when we're down in life.