It is difficult, to put an exact percentage on the number of left-handed people in the world but, estimates suggest the figure is around 10%. If we also estimate the population of the world a little under seven billion, that means the total number of left-handed people in the world is a bit less than 700,000,000. This is around half the population of China. There are a number of reasons why is it difficult to know, for sure, how many left-handers are there in the world. Firstly, it is not questioned on surveys, such as Censuses. That would be the most reliable source of information on the topic, but as many countries do not conduct a nation-wide Census and it is not on the questionnaire of those that do, there is no way of accurately knowing. Market research has been carried out, but again, it is of little use to know what percentage of Americans in a certain state are left-handed because, somewhere, like China may have a high proportion of left-handers, skewing the data. Also, there are still parts of the world where being left-handed is discouraged, even punished, so natural left-handers may not want to admit their left-handedness or might not even be aware of it. Finally, there are ambi-dextrous people. What category are they put in? At the best estimate, about 10% of people in the world are left-handed, but until a full and thorough world-wide investigation into the issue is carried out, we cannot know for sure. There are some positive aspects of being left-handed. Mensa, the organisation for people with a particularly high IQ, say, that they estimate that around 20% of their members are left-handed, about twice the average of the planet, showing that lefties have more than their fair share of brains.
