Mirror, mirror on the wall, who’s the brainiest of them all?
Visiting the Orcas
Friday evening: Scientists have several ways of measuring the size and complexity of the brains of different animals. However you look at orca brains, you have to conclude that these guys are super-intelligent.
After dinner, Lori Marino gave us a general intro to the brains and intelligence of orcas. Lori is a neuroscientist and Professor of Psychology at Emory University, and the founder of The Kimmela Center for Animal Advocacy.
Pound for pound, she told us, the orca brain greatly outsizes the human brain. It’s the fourth largest brain of all, while humans come in 23rd:
In terms of ratio of brain size to overall body size, however, the human brain comes out on top. On the next chart, the numbers refer to how many times bigger a brain is than what’s normal for an animal of that size. In other words, all the animals on this chart are “off-the-chart” brainy. The human brain is more than six times what you might expect for an animal our size. Orcas are about three times as brainy as you’d expect, and some other kinds of dolphins are almost five times what you’d expect.
Another way of measuring braininess is surface area, which is very important. We humans have to pack a lot of brain into a space that can’t grow any bigger (otherwise we’d get stuck while trying to be born). So the way we expand our brains is by having more surface area – i.e. more folds. Orcas have done the same thing, as you can see from the photos at the top. They pack a huge surface area into the available space in their heads.
Lori went on to explain how their brains are organized differently from ours. Audio and visual areas are closer together than in our case, and this makes for faster and more complex processing power.
So, who’s the brainiest of them all? In the famous tongue-in-cheek opening to the movie The Hitchhikers Guide to the Galaxy, we’re told that humans are the third most intelligent species on earth – a little way behind dolphins. (Above dolphins are mice, who turn out to be the physical protrusions into our dimension of a race of hyper-intelligent beings who commissioned construction of Earth to find the Question to the Ultimate Answer of Life.)
Sci-fi aside, and speaking from a strictly scientific perspective, Lori didn’t want to speculate on who has the most brain power. She said we simply don’t know, but a case could be made for saying that many dolphin species (of which orcas are one) outdo humans in terms of sheer intelligence and the processing power of their brains.
Lori is the author of the famous Mirror Self-Recognition Study, that showed, ten years ago, how dolphins are one of the few species with a sense of self – i.e. they know who they are and can think about themselves objectively. It was as a result of doing this study that she concluded that keeping dolphins in captivity is completely wrong, and she has been speaking out against it ever since. You can read about the study here, and check out an interview with her here.
Next: SeaWorld Shenanigans