MYTHCONCEPTIONS

267: BAD-SMELLING HUMANS The myth

Dogs have a great sense of smell, thousands of times more sensitive than that of humans who are essentially “nose blind”.

The “truth”

There is no hierarchy of mammalian olfactory ability, at least according to current thinking. The idea that there must be goes back to French anatomist Paul Broca (1824-80), who came up with the idea that humans were “non-smellers”, later known as “microsmatics”, because evolution had equipped us with free will at the expense of our “animalistic” senses, letting some parts of the brain wither while building up others. As is always the case in such stories, subsequent generations of scientists simply accepted what had been passed on without actually checking it. Broca and his successors never made any empirical examination of the sense of smell of various species: they determined what it should be, according to their untested hypothesis, based on the relative size of the olfactory bulb – which is now thought to be irrelevant, anyway. More recently, practical experiments on humans involving, for instance, tracking by scent like bloodhounds and distinguishing between two similar odours, have shown humans to have “excellent olfactory abilities” that are “similar to other mammals”.

Sources

www.science.org/doi/10.1126/science.aam7263; /www.theatlantic. com/science/archive/2017/05/alls-smell-that-ends-smell/526317/; www.ncbi.nlm.nih.gov/pmc/articles/PMC5512720/

Disclaimer

If that all sounds a bit dodgy to you, see if you can smell your way to the letters column, where tasty controversy is always made to feel welcome.

Mythchaser

I’ve heard this both ways round, and to me they both look mythical: either, if you fake a smile when you’re feeling miserable, that physical act will cause a neurological or chemical change which will improve your mood; or, if you fake a smile when you’re down, doing so will in fact deepen your happiness.