Sniffing Out Danger

By Stefanie Jones

Bloodhounds aren’t alone in their ability to sniff out danger. Scientists at Northwestern University in Chicago have discovered the human nose to be extremely effective where bad smells are concerned. They found that a single negative experience linked to an odour rapidly teaches us to identify and stay away from the smell in the future.

The study used two ‘grassy’ scents, one of which was paired with an electric shock. Perhaps unsurprisingly, subjects were much better at discriminating between the two smells when one was associated with pain.

Wen Li, lead author of the study and a postdoctoral fellow at the University, said, "It’s evolutionary. This helps us to have a very sensitive ability to detect something that is important to our survival from an ocean of environmental information. It warns us that it's dangerous and we have to pay attention to it."

Li also found differences between the way we remember the odours of things that we perceive to be dangerous and those we consider safe or pleasant. This means that the worse something smells to you, the more likely it is to be harmful.

It appears that the detection of bad smells is a mechanism based on emotional experiences intended to warn us away from danger. Or to put it another way, not only does that guy who sits next to you on the bus smell a bit funny, he might actually be dangerous to your health.

So next time you encounter a bad smell, beware – your nose may just be trying to tell you something.

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