## Archive for August 13, 2012

### Southpaw Summations

August 13 is Left Handers Day.

It’s interesting to me that left-handers chose the 13th as a day to honor themselves, since the number 13 is often associated with a lack of luck. After all, the word *sinister*, which implies that something evil or harmful is about to happen, derives from the Latin word *sinistra*, which means lefthanded. It comes from the Latin word *sinus*, referring to the pocket on a toga that always appeared on the left side.

My brother-in-law has a shirt that says:

Everyone is born right-handed.

Only the strongest can overcome it.

“Interesting theory,” I said.

“It’s only one of two possible theories,” he informed me. “The other is that everyone is born left-handed, but only the strongest can maintain it.”

Most sources say that about 10% of the population is left-handed, and most statistics show that there are more left-handed females than left-handed males.

Interestingly, some studies have found that left-handedness is higher in math teachers than in the general population. In particular, a statistically significant difference was found for male math teachers. It’s also the case that left-handed students score higher in math on the SAT.

It has been suggested that those without a language bias in the left hemisphere of the brain, who are left-handed at a higher rate than the general population, would have an advantage in mathematical ability. For this reason, one researcher said that there is not a higher than normal occurrence of left-handers among the mathematically gifted, but rather that there is a lower than normal occurrence of right-handers.

This reminds me of a famous syllogism:

- Ten percent of all car thieves are left-handed.
- All polar bears are left-handed.
- If your car is stolen, there’s a 10 percent chance it was taken by a polar bear.

Given this information about mathematical ability, it stands to reason that polar bears may have a penchant for both grand larceny and integral calculus.