Neuroscience Professor Irving Biederman of the University of Southern California says the click of comprehension triggers a biochemical cascade that rewards the brain with a shot of natural opium-like substances.

While you’re trying to understand a difficult theorem, it’s not fun, said Biederman. But once you get it, you just feel fabulous.

He says the brain’s craving for a fix motivates humans to maximize the rate at which they absorb knowledge. I think we’re exquisitely tuned to this as if we’re junkies, second by second, said Biederman

He hypothesizes knowledge addiction has strong evolutionary value because mate selection correlates closely with perceived intelligence. Only more pressing material needs, such as hunger, can suspend the quest for knowledge.

The same mechanism is involved in the aesthetic experience, Biederman said, providing a neurological explanation for the pleasure we derive from art.

He details his theory in an invited article in the latest issue of American Scientist.