either genes or some prenatal factors influence handedness! "Left Handed?" "Right Handed?"                                       10 % of population More diverse in speech production Genetically identical twins don’t share handedness More common among musicians, baseball players, and artists Bill Clinton, Ben Franklin, Da Vinci, and Marilyn Monroe are some famous left handers We more likely to have had birth stress DO we really die younger than righties? 90 % of population 95% of us process speech in the left hemisphere We prevail in all cultures Uniquely human, other primates are more ambidextrous Stanley Coren found that we tend to stay alive longer! either genes or some prenatal factors influence handedness!