Is imitational learning a driving factor for the population bias in human hand preference?

Area of Science:

• Neuroscience
• Evolutionary Biology
• Psychology

Background:

• Lateral preference, or handedness, is a common trait in humans and animals.
• Humans exhibit a strong population-level bias towards right-handedness, a unique phenomenon in the animal kingdom.

Purpose of the Study:

• To investigate the evolutionary role of social learning in shaping human right-handedness.
• To test if hand concordance between instructor and student enhances motor skill imitation.

Main Methods:

• 134 subjects observed videos of knot-making performed by either right- or left-handed individuals.
• Performance was measured by time to completion, number of attempts, and accuracy.
• Knot difficulty was varied to assess its interaction with hand concordance.

Main Results:

• Hand concordance between instructor and student significantly predicted faster and more accurate motor skill imitation.
• Increasing knot difficulty did not amplify the effect of hand concordance.
• Both hand congruency and knot difficulty were significant predictors of performance.

Conclusions:

• Concordance of handedness facilitates social learning of motor skills, enhancing speed and accuracy.
• This facilitation may have been a selective advantage, contributing to the human population's right-handed bias.
• Handedness may have been shaped by evolutionary pressures favoring efficient social learning.