Women are super-powered humans

Quite an interesting article about female sensory abilities in the Globe and Mail this weekend.

While men may be, generally speaking, stronger, tougher and faster - and endlessly celebrated as such - women seem to have (much less well-known and celebrated) enhanced sensory powers. And this is not just anecdote, it is scientific fact.

Women have greater touch sensitivity. Using fMRI technology, it has been shown that female babies' brains light up much more than males' when touched. Also, the smaller hands and fingers of women have just as many sensory receptors as men, meaning that they are more densely packed. Also, women have more thermosensitivity (for detecting subtle differences in temperature) in their hands than men. Almost a century ago, women were employed by the US Treasury Department to detect counterfeit banknotes by touch, a task men were not able to perform.

Women routinely outperform men in smell perception. Furthermore, this superiority is in all tested dimensions: identification, discrimination and detection thresholds. Women just have a better sense of smell, period. From postmortems, it has been found that women have 43% more cells and nearly 50% more neurons in their olfactory bulbs (where smell is analyzed in the brain) than men. Women can be trained to detect an odour 11 orders of magnitude lower in concentration than men.

It's the same with taste perception. Female tongues have more papillae and more taste receptor cells than male ones. This is the case for all "flavours" - sweet, sour, salty, bitter and umami - but it is especially notable in bitterness detection cells, possibly an evolutionary adaptation to guard against poisonous foods, which are often bitter to the taste. About 35% of women quality as "super-tasters" compared to just 15% of men.

Vision is more complex to test, but it seems that women have an edge in low light and in detecting subtle movements (like a change in facial expression), while men do better with high-contrast images and the speed of identifying fine detail. Another evolutionary development? Women, though, wins hands down with colour perception. Two of the cone cells that we use for colour vision are encoded on the X chromosome, of which women have two copies to men's one, resulting in a much smaller incidence of colour blindness in women (0.4%) than in men (8%). Women can also perceive finer gradations of colour than men, and some women even have four types of cone cells rather than three.

In auditory acuity, tests show women outperforming men by a substantial margin, both in hearing sensitivity and in speed of auditory responses. On the other hand, men tend to be better at pinpointing where a sound is coming from, and in detecting ultra-low frequencies. Women's hearing also declines more slowly, and later in life, than men's, partly due to environmental exposure (e.g. men have louder jobs, generally speaking), but also due to the hormone estrogen, which appears to help preserve the delicate structures of the inner ear.

All in all, this seems like a striking evolutionary dominance and fine-tuning in sensory abilities of all kinds. It's the hidden engine behind what has become known - and often derided - as "women's intuition".