International Left-Handers Day is on Aug 13 every year. Here are five things you may not know about left-handers.

1. Sinistrality is the formal name for left-handedness

It is based on the Latin word "sinistra," for "on the left".

Published research by social scientist John Dacey shows that left-handers have been regarded with a certain amount of suspicion by society as a whole through the ages.

British educational psychologist Cyril Lodowic Burt in 1937 suggested that left-handers were obstinate introverts, who declined to use their right hand to write with, not because they could not but because they would not.

Such association with educational backwardness and nonconformity led to parents and teachers at that time to force their children to use their right hand for writing and other manual tasks.

Psychological and educational research from the mid-fifties onwards however, helped to dispel such attitudes towards left-handers.

2.Many famous people are left-handed

Among them are American president Barack Obama, leader of India's independence movement Mahatma Gandhi, and theoretical physicist Albert Einstein. Closer to home, Prime Minister Lee Hsien Loong and 2014 Sportswoman of the Year bowler Shayna Ng.

3. Not only humans can be left-"handed"

More cats are left-pawed than right-pawed. According to Australian site Cat World, out of every 100 cats, about 40 are left-pawed, 20 are right-pawed, and 40 are ambidextrous.

4. Specialty stores sell products just for left-handers

There are stores that sell products specially made for left-handed people. Such products include school supplies like rulers, pens and notebooks, baking supplies like measuring cups mittens and spatulas, and all kinds of cutting tools.

In Singapore, online store Simply Lefty selling items like kitchen utensils, tools and stationery designed for left-handers was set up in 2009. It however appears to have closed down.

5. Left-handers may be predisposed to certain occupations

In a 1996 study, Harvard Medical School researchers found that orthopedic surgeons, librarians and mathematicians were mostly right-handed, while attorneys and architects were, as a group, "either the least right-handed or the most left-handed."

Other studies have shown that there are more left-handed people working as artists and musicians, and in university settings.

Sources: wnep.com, Coventry Telegraph, Linda Gan