TED-Ed: Why are some people left-handed? - Daniel M. Abrams

The video explores the concept of handedness, focusing on why a minority of people are left-handed. It delves into the historical prevalence of left-handedness, genetic influences, and evolutionary theories. The video highlights the competitive advantages left-handers have in sports and combat, while also discussing the cooperative pressures that favor right-handedness. It concludes with a model suggesting that the balance between competition and cooperation has maintained a stable minority of left-handers throughout human evolution.

What is a common societal practice regarding handedness in many parts of the world?

• Encouraging left-handedness

• Promoting ambidexterity

• Forcing children to use their right hand

• Allowing children to choose their dominant hand

How can handedness be predicted before birth?

• By the mother's diet

• Through genetic testing

• Based on the fetus' position in the womb

• By the father's handedness

What is the chance of a child being left-handed if both parents are right-handed?

• 10%

• 25%

• 50%

• 75%

What evolutionary concept explains the advantage of left-handed individuals in competitive scenarios?

• Negative frequency-dependent selection

• Genetic drift

• Natural selection

• Positive frequency-dependent selection

In a purely competitive world, what percentage of the population would be left-handed?

• 75%

• 10%

• 25%

• 50%

Why are left-handed individuals less successful in a purely cooperative world?

• They are more adaptable

• They have higher accident rates

• They are more competitive

• They are better at using tools

What percentage of top golfers are left-handed, illustrating the impact of tool sharing?

• 4%

• 10%

• 25%

• 50%