What percentage of the population are left-handed?
For years, it has been widely accepted that 1 in 10 people are left-handed. However, research studies of a reasonable size to back up this figure are very hard to find. Recently, small studies (usually among children) have come up with figures of between 12% and 15% of the population and it has been argued that perhaps this increase is due to social acceptability of left-handedness which has never before been the case. The most recent study, by Prof. Chris McManus who has conducted widespread research into the genetic causes of handedness, has concluded that 13% of the population are currently left-handed. It is widely believed that there are slightly more left-handed boys with normally about 5 left-handed boys for every 4 left-handed girls. A study by Nigel Sadler of 3,000 schoolchildren in Waltham Forest, London recorded an even higher percentage of boys (11.6%) than girls (8.6%). Some research has linked left-handedness to the level of testosterone present in the womb before birth,
