Research suggests that human handedness is mostly caused due to genetic factors.
Brain dominance is another factor that plays a role in hand preference. Majority of the world population is right-handed.
Brain’s left hemisphere controls language in right handed people, whereas the right hemisphere controls language in left-handed people. However, language is processed by the left hemisphere or both in some left-handers.
Males are more likely to be left-handed than females. Twins have 17% possibility of being left-handed, compared to general individuals having 10% possibility. Left-handedness has a complicated genetic basis.
Children of parents who are both left-handed have only 26% chance of being left-handed. Left-handedness is also influenced by other factors such as the environment and individual’s development. Activities involving throwing or holding things in early life can also influence the use of hand later.
This infographic presents some scientific and general facts about hand preference and some worst things that lefties have to experience in their life.