Why are women more sensitive than men? - Scientists have come up with a novel explanation. They say it's all in the smaller fingertips.
They have found that petite fingers have a more developed sense of touch, making them more sensitive.
This finding explains why women tend to have better tactile acuity than men, because women on average have smaller fingers.
"Neuroscientists have long known that some people have a better sense of touch than others, but the reasons for this difference have been mysterious," said Daniel Goldreich, of McMaster University in Ontario, one of the study's authors.
"Our discovery reveals that one important factor in the sense of touch is finger size," he added.
To determine why the sexes have different finger sensitivity, the researchers first measured index fingertip size in 100 university students.
Each student's tactile acuity was then tested by pressing progressively narrower parallel grooves against a stationary fingertip - the tactile equivalent of the optometrist's eye chart.
The researchers found that people with smaller fingers could discern tighter grooves.
Ethan Lerner, of Massachusetts General Hospital, who is unaffiliated with the study, said:
"The difference between the sexes appears to be entirely due to the relative size of the person's fingertips. So, a man with fingertips that are smaller than a woman's will be more sensitive to touch than the woman."
The study has been published in the Dec. 16 issue of The Journal of Neuroscience.