Hate Magpies? Too Bad They Might Explain the Evolution of Human Brains

The social intelligence hypothesis is an attempt to explain why humans—when compared with all other species—have such large and complex brains. The theory is our intelligence came about as a product of cooperating with others, and so by living in large groups our neolithic ancestors evolved larger brains.

Intuitively the hypothesis seems plausible, but researchers at the the University of Western Australia wanted to see if such a trend appears in animal populations, or more specifically, in magpies. And apparently it does.

The study, published in Nature, found that intelligence varies between magpies from differently sized flocks, and that magpies from smaller flocks actually seem quite stupid.

Researchers gave magpies from several flocks four different tasks. The tests measured "inhibitory control, associative learning, reversal learning, and spatial memory." And as lead researcher Benjamin Ashton told Australian Geographic, there were some noticeable results.

"For the associative learning task there was an individual from a group size of 12 that took 10 trials to learn the association between colour and food reward, whereas there was an individual from a group size of three which took 62 trials."

Ben admitted that a possible weakness of the tests were that the individual magpies might have just eaten more, giving them more energy. But this is only a maybe, as results seem repeated across the board.

"We found that individual performance was correlated across all four tasks, so an individual that performed well in one task performed well in all four, this is evidence of a general cognitive factor, or what we call general intelligence in humans."

Ben believes that magpies were the perfect study species in this test because all live in groups ranging from three to 15 individuals. And all from populations that had been carefully monitored for more than five years, so researchers could cross reference findings with previous observations.

Ben says the next step is to examine what it is, exactly, about large-flock-life that encourages intelligence, which could obviously have some interesting implications for human education.