Why do people vote against their own interests?

This article appeared on the BBC news website today, having been broadcast on Radio 4 this week. This perceptive observer explains that in order to succeed in the US political arena, the candidates with logic on their side must behave as reprehensibly as the anti-logic parties, by so doing appealing to the largest number of voters. Unfortunately though, the people to whom a reasoned argument appeals won't want to vote for them...this is great for comedians, not so great for citizens.

Perhaps what we need is a national wife, not a "leader": someone who can quietly keep everything running, and is smart enough to let a fool go on thinking he is "right" & that he is running the show when he is not, and that everything is his idea.
I suspect our problems are more chemical than ideological, or anything else. Reduce the testosterone levels to bare minimum, and see if things don't improve.