Some bees love a good adventure while others prefer to hang out at the hive, and a new analysis of bee brains suggests some of the same chemicals that affect human personality could explain why.
Honey bees are known to have a structured society in which different bees serve different tasks -- some work as nurses while others forage for food, for example.
But within these ranks, it appears that bees have different personalities, said the study in the journal Science that examined the difference between nest scouts that forage for new food sources and those that do not.
"There is a gold standard for personality research and that is if you show the same tendency in different contexts, then that can be called a personality trait," said lead author Gene Robinson, professor of entomology and neuroscience at the University of Illinois.
Researchers differentiated between bees by setting up new feeding posts with unique colors and smells, one by one over several days, and tracking which bees liked to test new chomping grounds and which ones stuck with the familiar.
When they examined the brains of the adventurous bees, they found differences in gene expression related to the same molecular pathways that regulate novelty-seeking in mammals and humans -- including catecholamine, glutamate and gamma-aminobutyric acid (GABA) signaling.
These chemicals in the brain are known to influence the level of reward a person feels when seeking new experiences. The differences in gene activity between the two types numbered in the thousands.
The team further discovered that treating bees so that levels of glutamate and octopamine would be higher caused non-scout bees to start exploring.
When they blocked the pleasure chemical dopamine, the bees scouted less than before.
"Our results say that novelty-seeking in humans and other vertebrates has parallels in an insect," Robinson said. "One can see the same sort of consistent behavioral differences and molecular underpinnings."
The research also suggests that the same sort of genetic toolkit evolved among bees, animals and humans, and that adventuring was a worthwhile trait to preserve because it could help species find new sources of food.
"It looks like the same molecular pathways have been engaged repeatedly in evolution to give rise to individual differences in novelty-seeking," Robinson said.
The study was funded by the National Science Foundation, National Institutes of Health and the Illinois Sociogenomics Initiative.