Even among natural left-handers (in about 12.5 % of any human population, language skills are localized in the cortex of the left hemisphere in all but about 2.5% of the cases. Some of these are individuals who received damage to the left hemisphere in childhood which, presumably, prevented language from localizing there; however, we don't know why language localizes in the right hemisphere of the brain in about one in fifty healthy adults. Like right or left handedness, it seems to correlate with nothing else in particular.