’ : dolphins does it take to screw in a lightbulb? Zero, because there are no dim bulbs in the dolphin world.
Cetaceans, the group of animals that includes dolphins and whales, are intelligent, big-brained creatures that form friendships and social traditions similar to those of humans. They also play, babysit, hunt cooperatively and teach one another how to do things. “They have signature whistles,” says study co-author Michael Muthukrishna, an assistant professor of economic psychology at the London School of Economics. “They actually have names for each other.”
A new study published in Nature Ecology and Evolution looks at how the size of an animal’s brain affects its social activity. Researchers at the University of Manchester, the University of British Columbia, Stanford University and the London School of Economics and Political Science gathered data from years of studies on the brain sizes of 90 species of whales and dolphins, as well as from studies by field scientists on the breadth of social behaviors of wild dolphins and whales, such as using language, sharing goals, teaching one another, acting with empathy and making decisions based on consensus. By assigning a value to each species based on how often it engaged in these social actions, the scientists were able to plot the sociability and brain size. The graph showed that as brain size increased, so did the breadth and number of social behaviors.
The findings may teach us about ourselves as well. They suggest that the evolution of human brain size and our social instincts may be linked. However, dolphins are not about to evolve into bipedal, anthropomorphs with advanced societies like those of humans. Although whale and dolphin societies are similar socially to those of humans, the aquatic animals lack certain abilities necessary for human evolution. They can communicate well and hunt efficiently, but they do not have thumbs, which are required to make complex tools. Furthermore, the ability to cook was an important milestone in human evolution, and this is an advantage we will always have over dolphins. “They will never discover fire,” says Muthukrishna, “because it’s very difficult to light a fire underwater.”