Senses of wonder

Human powers of perception are far more complex than just the famous five of sight, hearing, smell, taste and touch.

- MARK BROATCH

We have five senses, right? Sight, hearing, smell, taste, touch. Plus that one that tracks where your body and limbs are in space, particularly useful for the likes of gymnasts and platform divers. And maybe one for pain. Seven in total. Ten tops.

But humans may, in fact, have as many as 52 senses. And the ones we have, rather than being the also-rans of the animal kingdom, are incredibly sensitive. Thanks to our big brains, we can detect maybe 10 million colours, perhaps a trillion smells. With our fingers we can detect a layer of difference one molecule thick. We have neurons in our noses and our muscles, taste receptors right through our body. Our senses are actually extraordinary.

How might we have dozens of senses? Take touch, for instance, which might include perception, pain, heat and cold.

“There are so many receptors that make up touch that, strictly speaking, they are different receptors,” says Ashley Ward, a professor of animal behaviour at the University of Sydney. “It’s almost like an orchestra of different senses which come together to give the perception of touch.”

Our senses actually compare pretty well to those of many animals, says Ward, the author of a new book,