New study on brain size and cultural behaviour in whales and dolphins

Authors of a new scientific paper published in the journal Nature Ecology & Evolution have put forward the theory that there is a link between brain size and social and cultural behaviour in whales and dolphins.  The researchers looked at 90 different species of whales and dolphins and suggest the bigger their brains, the more complex their lives can be.

Commenting on the new paper, WDC Research Fellow Philippa Brakes said: “It is an interesting study, that will no doubt provoke some response from the neuroscience and behavioural ecology community. I agree with others that we have to be careful not to fall into the trap of seeing humans as the pinnacle of evolution, which other species may be transiting towards, when in fact all species are beautifully and constantly shaped by the forces of evolution associated with the niche which they inhabit. Just because dolphins don’t have thumbs and will never be capable of the development of material technologies like ours (as noted here), doesn’t mean they are less well adapted for their environment, any more than the fact that I can’t echolocate or hold my breath for half an hour.

"There’s also some acknowledged risk in using brain size as a direct correlate for intelligence. Ask any parrot. Structure can be as important as size. What is interesting here though is this idea that there appears to be a relationship between the degree and type of sociality within whales and dolphins and brain size. Importantly, this research indicates that it isn’t the absolute numbers in a social group that matters, but the types of social relationships between individuals that may influence brain evolution.

"Although the research uses records of social behaviour from both a wild and captive setting, which can be problematic, particularly when assessing the veracity of social behaviour in artificial groups in captivity, the authors argue that their study provides some first evidence that ‘the richness of cooperative social behaviours increases with brain size and group stability in whales and dolphins’. The research also challenges some of the existing ideas about cetacean brain structure and the evolution of sophisticated, socially complex behaviour and provides further evidence against the theory of ‘thermogenesis’ i.e. that whales’ and dolphins’ large brains merely have a heat-producing function.”

The social and cultural roots of whale and dolphin brains
Kieran C. R. Fox, Michael Muthukrishna & Susanne Shultz
Nature Ecology & Evolution (2017)

Find out some amazing facts about intelligence in whales and dolphins.

Sperm whales have the largest brain of any whale or dolphin.
Sperm whales have the largest brain of any whale or dolphin.