Whales and dolphins lead 'human-like lives' thanks to big brains, says study

The cultural brain hypothesis of human development could also explain cetaceans forming friendships - and even gossiping

Life is not so different beneath the ocean waves. Bottlenose dolphins use simple tools, orcas call each other by name, and sperm whales talk in local dialects. Many cetaceans live in tight-knit groups and spend a good deal of time at play.

That much scientists know. But in a new study, researchers compiled a list of the rich behaviours spotted in 90 different species of dolphins, whales and porpoises, and found that the bigger the species' brain, the more complex - indeed, the more "human-like" - their lives are likely to be.