Who has a better sense of touch - women or men?
Based on most recent studies, even a neuroscientist may jump to the conclusion that women have a superior ability to perceive fine surface details with their finger tips. Women, on average, tend to score 10-per-cent better than men on so-called "tactile-acuity" tests.
But a new study, led by Daniel Goldreich of McMaster University in Hamilton, has demonstrated that finger size - not gender - determines who is tops in touch.
For the study, the team recruited 100 university students. Participants' touch perception was tested by pressing their index fingers against progressively more narrow parallel grooves cut into pieces of plastic - the tactile equivalent of an optometrist's eye chart, explained Dr. Goldreich.
During the test, they were asked to identify the direction of the lines - either up and down, or from left to right. Eventually, the grooves came so close together that the plastic surface felt perfectly flat.
The results, published in the Journal of Neuroscience, revealed that people with the smallest fingers had the best sense of touch.
Dr. Goldreich now believes women generally do better on tactile tests simply because they tend to have smaller hands than men, not because they have an intrinsically superior sense of touch. "A man who has fingers the same size of a woman will have, on average, the same sense of touch she has," Dr. Goldreich said. "And a man with even smaller fingers will have a better sense of touch than the woman."
So, why would smaller fingers win hands down? The researchers suspect that tinier digits likely have more closely spaced sensory receptors. "Either we have a fixed number of receptors and, as the fingers get bigger, the receptors get more sparsely distributed. Or else the number of receptors does not grow in proportion to finger size," Dr. Goldreich speculated.
"Much like pixels in a photograph, each skin receptor sends an aspect of the tactile image to the brain - more receptors per inch supply a clearer image," says a statement released with the study.
The study raises the possibility that people with small fingers may have a special aptitude for learning certain jobs, ranging from weaving to surgery.