Peer Pressure Forced Whales and Dolphins To Evolve Big Brains Like Humans, Says Study (qz.com)

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.

Comments

However, by the time you get as social as insects

[Anonymous Coward]

The size of the brain doesn't seem to matter so much anymore.

I see some logic vs Lysenkoism at play here..

Dolphins?

[mentil]

My understanding is that dolphins' large brains are mostly glial cells, which are there to keep their brains warm, rather than actual neurons. That's why their brains are so large yet they're only about as intelligent as dogs. Correlations made with dolphin brain size may not end up being very meaningful.

It Makes Perfect Sense

[careysub]

It is clear that high intelligence is not necessary for successful survival, there is no general trend toward progressively evolving high intelligence in any lineage on land but the Hominidae (and it stalled among all the branches of the Great Apes but one). Curiously modern humans 80,000 years ago went through a near extinction event, with the world population dropping to a few thousand individuals, intelligence equivalent to our own did not give them a huge survival advantage at that time.

But success in a society creates an intelligence arms race. More powerful brains processing social information give an edge in dominating reproduction opportunity through most of evolutionary history. (Debates about whether perhaps the opposite is true at this moment in history I leave aside.)

Re:Human peer pressure shrinks brain

[Immerman]

Indeed, the problem for us nerds/geeks was not that we were intelligent, it was that we chose to apply that intelligence to "interesting things" rather than social maneuvering. I knew plenty of smart kids who were quite popular, I just found their hobbies utterly uninteresting.

Fortunately, that problem faded greatly upon entering adulthood - there's obviously still a lot of brainy social misfits, but there's far less social advantage to harassing them, and far more potential mates who have grown past their raging hormones to appreciate them.

I suspect a great deal of the problem is this recent concept of "teenager" artificially imposing an extended "child" status on individuals who are biologically entering the period where they should be establishing their position within the tribe by making genuine contributions. Instead we keep them locked up in day-care institutions with nothing productive to do all day, so that social maneuvering is basically the *only* skill that contributes to social status. Any time you put humans in that situation it tends to bring out the worst in them - be it prison or upper-middle class housewives lunching and back-biting to pass the time.