Two researchers in Mississippi observed dolphins at play and cataloged 317 different game-like behaviors.

When Stan Kuczaj and Lauren Highfill were snorkeling among some rough-toothed dolphins off the coast of Honduras last year, they saw an intriguing game among the animals.

Two adults and a youngster were passing a plastic bag back and forth, as in a game of catch, the two researchers wrote in the October issue of the research journal Behavioral and Brain Sciences.

A pantropical spotted dolphin (Stenella attenuata) skips on its tail over the water. No one knows why dolphins do this, but some scientists say it could be for fun. (U.S. National Oceanic & Atmospheric Adminstration)

When the adults passed it to the youth, they did so more carefully than to each other, releasing it just in front of the youth’s mouth, as if to make it easier to catch.

After years of studying dolphins at play, Kuczaj and his colleagues have reached some surprising conclusions: dolphin games show remarkable cooperation and creativity. Dolphins seem to deliberately make their games difficult, possibly in order to learn from them. And such pastimes may play a key role in the development of culture and in evolution—both among dolphins and other species, including humans.

Games “may help young animals learn their place in the social dynamics of the group,” wrote Kuczaj, a psychologist with the University of Southern Mississippi in Hattiesburg, Miss., and colleagues in a paper to appear in the International Journal of Comparative Psychology.

“The innovations produced during the interactions of young animals may be important sources for the evolution of animal traditions, as well as the adaptations that may lead to more successful individuals and species,” they added.

The researchers based their findings on five years of research with a group of 16 captive bottlenose dolphins, and additional studies on wild dolphins.

Evolutionary theory holds that species gradually change because the rare mutations that are helpful for an animal spread through the population, eventually creating new species. Natural selection, a process in which only the organisms well-suited for their environment survive, spreads these genes by ensuring that those who have them live longer and reproduce more.

Many researchers have suggested that in line with this theory, animals inherited a predisposition to play because “it helps animals gain knowledge of the properties of objects, perfect motor skills, and recognize and manipulate characteristics of [their] environment,” Kuczaj’s group wrote.

One sign of the importance of play, they added, is that many animals play at the risk of loss of life and limb, including dolphins.

The scientists also cited research suggesting young dolphins deliberately make their games as hard as possible, possibly to enhance the learning experience.

More here.