Big Brains Enabled Whales and Dolphins to Lead “Human-Like Lives”

Fagjun | Published 2017-10-20 14:33

Researchers find a link between the big brains of whales and dolphins and the cetaceans’ ability to have social interactions as well as cultural behaviors.

How much do we have in common with cetaceans?



Life is very different under the sea--well, maybe not so different after all. We’ve all probably heard that dolphins and other cetaceans are smart, and they show this in different ways. Researchers have found that dolphins associate certain sounds with certain individuals. Sperm whales, meanwhile, have regional dialects. Bottlenose dolphins in particular have also been found to be able to use tools. Several cetacean species live in close-knit groups and are often observed to be at play.


These, of course, are already quite impressive. However, according to a new study, the lives of cetaceans are much richer than we previously thought. Researchers studied a total of 90 different species of dolphins, whales, and porpoises and found that the bigger the brain of the cetacean, the more “human-like” their lives are.

How Smart Cetaceans Really Are


Footage of whales playing with dolphins, by Whale Watching Sydney



These findings suggest striking similarities between the evolution of humans and cetaceans. The most remarkable similarity is that humans and cetaceans both display cultural behaviors as well as complex social relationships.


“Similar pressures and possibilities in the environment can select for a similar outcome,” says Kieran Fox, one of the co-authors of the study. Thus, like humans, cetaceans may have developed their level of intelligence as a coping mechanism for living in large and complex groups.


The researchers suggest that encephalization, a process that refers to the expansion of an animal’s brain, may have something to do with the development of complex cultural and social behaviors in cetaceans. The findings of the study show remarkably complex and advanced behaviors like playing with whales, altruism towards members of other species, raising unrelated young, and perhaps even gossiping. Researchers found that dolphins use certain sounds to indicate individuals that are not present, suggesting that dolphins may be capable of talking about others behind their back.


It’s also likely that cetaceans, like humans, learn the most when they’re with others in their social group. This may explain why some species are less complex than others. Species with bigger brains have large groups of about 20 individuals. Meanwhile, those with smaller groups tended to also have smaller brains.

The Chicken-and-Egg Conundrum



This research now presents a chicken-and-egg conundrum: which came first, the complex social behaviors or the big brains?


According to Fox, neither one really came first, but instead formed something called a “positive feedback loop”. An animal has to have a bigger, more powerful brain to learn complex social behaviors and other skills. Meanwhile, an animal that has evolved to have that kind of brain is more capable of learning. “That’s the theory to this extremely powerful driver of brain evolution,” says Fox. “Once it gets going, you get some brain tissue that supports (social skills), then these individuals are going to do really well, because social cooperation and learning and very powerful survival strategies.”


This means that natural selection will ensure that future generations will inherit these expanded brains. These species thus develop complex social and cultural interactions.

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