Humans like to think of themselves as the only species that demonstrate introverted and extroverted behavior. But according to a new study, sharks have individual personalities as well that affect whether they join groups of participate in solitary activities.

Sharks were studied individually in groups of ten and switched to new habitats. Despite the environment change, the sharks still showed their individuality- some had social habits, while others were more solitary.

University of Exeter researchers, in collaboration with the Marine Biological Association of Plymouth, England, studied 100 spotted catsharks in groups of ten each. Despite different habitats- some were rocky and complicated, while others were simple plain tanks- the sharks consistently exhibited different social preferences.

Sharks that formed larger groups consistently participated in this practice, while other sharks demonstrated antisocial behavior or formed very small groups.

“The results were driven by different social preferences, that appeared to reflect different strategies for staying safe,” said Dr David Jacoby, a lead author of the study.  “Well-connected individuals formed conspicuous groups, while less social individuals tended to camouflage alone, matching their skin color with the color of the gravel in the bottom of the tank.”

The study’s detailed results were highly praised among the zoological community. Sharks were studied night and day to determine behavior and group formation.

Over the past ten years, animal researchers have begun to study distinct animal personalities within groups. Highly intelligent species such as dolphins and chimpanzees have already demonstrated individual behavioral patterns.

According to Professor William Hughes, a University of Sussex animal behavior expert, “Probably all animals show it, to some extent.” On the study, he commented, “It’s a very nice piece of work. It provides some pretty reasonable evidence that sharks show a form of social personality.”

The University of Exeter isn’t the only organization studying personalities within species. Jean-Sebastian Finger, a Humboldt University doctoral candidate, is currently researching distinct personalities within the lemon shark population off the coast of the Bahamas.

Mr. Finger was not surprised to learn of the University of Exeter’s results.  “Personality has been seen everywhere – in almost every taxon of animals. Sharks haven’t really been tested before.”

The University of Exeter group tested sharks in captivity, while Mr. Finger is testing sharks in the wild. The two groups are eager to collaborate results to demonstrate whether personalities are changed in these two different experiments.