Maybe Homer Had it Right

My final exams are nigh. That's why, when I saw the title of this article today in the Science Times "Lots of Animals Learn, But Smarter Isn't Better," I didn't know whether to laugh or cry.
Carl Zimmer's article describes the experiments of a lab at the University of Fribourg which involve flies who are conditioned not to like one kind of jelly:

It takes just 15 generations under these conditions for the flies to become genetically programmed to learn better. At the beginning of the experiment, the flies take many hours to learn the difference between the normal and the quinine-spiked jellies. The fast-learning strain of flies needs less than an hour...but the flies pay a price for fast learning...About half the smart flies survived; 80 percent of the ordinary flies did.

Dr. Kawecki suspects that each species evolves until it reaches an equilibrium between the costs and benefits of learning. His experiments demonstrate that flies have the genetic potential to become significantly smarter in the wild. But only under his lab conditions does evolution actually move in that direction. In nature, any improvement in learning would cost too much...

"Humans have gone to the extreme," said Dr. Dukas, both in the ability of our species to learn and in the cost for that ability."

Neurosis come to mind as a cost of brain power combined with the cost of leisure (which seems to be the goal of so many developed brains). Do I really need a PhD - especially one to study brains? I don't know... maybe I'm smart enough.

(I'm realizing from TJ's comment that that last sentence sounds conceited. I meant more that I was worried about the liabilities of adding any brain power (whatever my baseline) given the fate of the flies, not that I think I'm smart.)