View full lesson: http://ed.ted.com/lessons/why-are-some-people-left-handed-daniel-m-abrams
Today, about one-tenth of the world’s population are southpaws. Why are such a small proportion of people left-handed -- and why does the trait exist in the first place? Daniel M. Abrams investigates how the uneven ratio of lefties and righties gives insight into a balance between competitive and cooperative pressures on human evolution.
Lesson by Daniel M. Abrams, animation by TED-Ed.
TED, TED-Ed, TEDx, Left-hand, Left-handed, Proper hand, Right-hand, Right-handed, Identical twins, Handedness, Parents, Genetics, Competitive pressures, Cooperative pressures, Sports, Fighting hypothesis, Negative frequency-dependent selection, Evolution, Evolutionary advantage, Baseball, Switch hitter, Golf, Right-handed world, Equilibrium