An anonymous reader quotes a report from Quartz: The human brain has evolved and expanded over millennia to accommodate our ever-more-complex needs and those of our societies. This process is known as "encephalization" and has given us the big brain we need to communicate, cooperate, reach consensus, empathize, and socialize. The same is true for cetaceans, like whales and dolphins, it seems. These sea creatures also grew big brains in order to better live in societies, according to a study published on Oct. 16 in Nature Ecology & Evolution. According to Michael Muthukrishna, an economic psychologist at the London School of Economics and co-author of the study, the researchers used two related theories, the Social-Brain Hypothesis and the Cultural-Brain Hypothesis, to make predictions about various relationships between brain size, societal organization, and the breadth of behaviors the cetaceans would display. Then they tested these predictions by creating and evaluating a comprehensive database of cetacean brain size, social structures, and cultural behaviors across species using data from prior studies on 90 types of whales and dolphins. The study found that cetaceans had complex alliances and communications, played and worked together for mutual benefit, and could even work with other species, like humans. Some also have individual signifiers, sounds that set them apart from others, and can mimic the sounds of others. In addition, it found that brain size predicted the breadth of social and cultural behaviors of these marine creatures (though ecological factors, like prey diversity and latitudinal range, also played a role). The researchers concluded there was a tie between cetacean encephalization, social structure, and group size.Read more of this story at Slashdot. Click here to read full news..