Ant and human, eyeball to eyeball. We are linked with ants in ways both surprising and profound. Humans, as you may have guessed, are the other dominant social organism on the planet. Both ants and humans divide labor and form complex social networks. Both work in groups to accomplish tasks—leaf nests, Maya temples—that no individual could complete alone. Both raise their young in families. Both use the same class of neurotransmitters—biogenic amines like dopamine and serotonin—to govern behavior. Both go to war.
There are differences, of course, and here’s a big one: with brains that are large relative to their body size, humans build skyscrapers and societies. Ants weave nests, navigate dark forests, and even farm food with brains that are downright diminutive. This may not seem surprising at first, but consider this: only a measly 2 percent of insects—ants, bees, some wasps and termites—live in societies. Most insects are like fruit flies, buzzing around, doing their own thing, every fly for himself. So the ultrasocial ants, operating with brains up to 600 million times smaller than humans, made even Charles Darwin step back in awe. “The brain of an ant is one of the most marvelous atoms of matter in the world,” he wrote in 1871, “perhaps more so than the brain of man.”
How can ants do so much, with such tiny brains? That leads to the central question of College of Arts & Sciences Professor James Traniello’s research: how does collective intelligence influence brain evolution? And how does brain size and shape and neurochemistry relate to social behavior?