New study examines complexity of dolphin culture; researchers determine that brain size correlates with “human-like” behaviors and societies

In a major study published in Nature Ecology & Evolution, the complexity of Cetacean culture and behavior has been linked to the size of their brains.

Like other mammals, whales and dolphins have tightly-knit family groups called pods whereby they follow certain social structures and form complex relationships, similar to human societies. The research was a collaboration between scientists at The University of Manchester, The University of British Columbia, Canada, The London School of Economics and Political Science, and Stanford University. A first of its kind, the study has collected and compiled a large dataset from 90 different species of dolphins, whales, and porpoises. The study reveals overwhelming evidence of the animals’ sophisticated social behaviors relative to their brain size and brain expansion (known as encephalization).

The findings reveal several behavioral similarities with humans and primates, such as:

  1. Communication – “Talking” to each other through complex vocalizations and regional dialects;
  2. Name recognition – Signature whistles unique to individuals;
  3. Cooperation – Working together in hunts and exchanging hunting techniques;
  4. Alloparenting – Looking after calves that aren’t their own;
  5. Alliance – Working together for mutual benefits;
  6. Social play – Honing skills through play; and
  7. Interspecies interaction – Working with different species such as humans.

Dr Susanne Shultz, an evolutionary biologist in Manchester’s School of Earth and Environmental Sciences, said: “As humans, our ability to socially interact and cultivate relationships has allowed us to colonise almost every ecosystem and environment on the planet. We know whales and dolphins also have exceptionally large and anatomically sophisticated brains and, therefore, have created a similar marine based culture.”

The study shows that co-evolution of brains, social structure, and behavioral patterns of marine mammals is an apparent parallel to the large brains and extremely social behaviors of humans and other primates on land.

“Unfortunately, they won’t ever mimic our great metropolises and technologies because they didn’t evolve opposable thumbs,” said Shultz.

The team used the dataset to test the social brain hypothesis (SBH) and cultural brain hypothesis (CBH), which were originally developed to explain the large brains of primates and other land mammals and its connection to intricate and elaborate behaviors. (Related: Highly intelligent Elephants adopt stealth guerilla warfare tactics to stay alive by avoiding hunters.)

The hypotheses point out that large brains are an evolutionary response to highly complex social environments. This is the first time that the hypotheses have been used on intelligent marine mammals.

Dr Michael Muthukrishna, Assistant Professor of Economic Psychology at LSE, further explained the significance of the study: “This research isn’t just about looking at the intelligence of whales and dolphins, it also has important anthropological ramifications as well. In order to move toward a more general theory of human behavior, we need to understand what makes humans so different from other animals. And to do this, we need a control group. Compared to primates, cetaceans are a more ‘alien’ control group.”

Dr Kieran Fox, a neuroscientist at Stanford University, said the study gives rise to a new question about how diverse patterns of brain structure in different species manifest highly similar cognitive and social behaviors.

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