Heritability of hand preference in chimpanzees (Pan)

Area of Science:

• Primate behavior
• Behavioral genetics
• Evolutionary psychology

Background:

• Hand preference, or handedness, is a complex trait observed across many species.
• Understanding the factors influencing handedness, such as genetics and environment, is crucial for evolutionary studies.
• Previous research has explored handedness in non-human primates, but heritability remains a key question.

Purpose of the Study:

• To investigate the heritability of hand preference in chimpanzees.
• To determine the relative contributions of genetics and rearing environment to handedness in this species.
• To compare patterns of hand preference between offspring and parents, and among related individuals.

Main Methods:

• Studied 76 chimpanzees, comparing hand preference (strength and direction) between offspring and their biological parents.
• Analyzed hand preference patterns among half-siblings raised in different environments.
• Utilized two distinct measures to assess handedness.

Main Results:

• Offspring demonstrated the same hand preference as their biological parents significantly more often than predicted by chance for both measures.
• Patterns of hand preference among half-siblings showed significant deviations from chance expectations.
• The rearing environment did not account for a significant proportion of the variance in hand preference.

Conclusions:

• The findings strongly suggest a significant heritability component in the expression of hand preference in chimpanzees.
• Genetic factors appear to play a more substantial role than environmental factors in shaping handedness in this species.
• This study provides robust evidence for the genetic basis of behavioral laterality in non-human primates.