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Sunday, December 19, 2010

Animal Intelligence

A person’s IQ is accepted as a way of measuring how intelligent they are but have you ever wondered how intelligent a horse is or a cat? [click on table to enlarge it]

I was fascinated when I read that an EQ [Encephalization Quotient] test has been devised to give a rough measure of the intelligence of different species.

The test involves knowing the average weight of the brains of an animal but it turns out that the larger an animal is, the more brains it needs to just do the things that keep it alive, like breathing and moving around, etc. That problem was overcome by taking a creature’s lean body weight into consideration in comparing brain sizes.The larger the weight of the brain relative to the body weight, the more of the brain is available for learning new things and applying that knowledge – or in other words, the more intelligent.

It turns out having a larger brain is not necessarily better, because the larger the brain, the more energy it takes to develop it and feed it. [In my ‘Memory’ post I mentioned that our human brains actually uses 1/4 of the total energy our bodies require!]. But Mother Nature is usually frugal about using energy and apparently animals tend to just develop the size of brain they need and that's about it.

In the face of that evidence, the often repeated ‘home truth’ that we humans don’t use half the capacity of our enormous brain is questionable. Neuroscience is such a hot research area these days – I’m hoping I’ll be around long enough to learn more about this 'extra' unused capacity!

You may have noticed that I’ve recently set myself the goal of writing something to post every Friday night - but am late this week. That’s because, in trying to explain the surprises I found in the EQ table, I got carried away. The next post will probably be about the relationships we have to animals and some ideas about the why. Meanwhile - Happy Holidays! Rie