Evidence for a maternal effect on infant hand-use preferences

Area of Science:

• Developmental Psychology
• Human Genetics
• Neuroscience

Background:

• Left-handedness is more common in offspring with left-handed parents.
• A maternal effect has been observed, with left-handed mothers having more left-handed offspring than left-handed fathers.
• Previous research has not specifically investigated this maternal effect in infant hand-use preferences.

Purpose of the Study:

• To investigate the maternal effect on hand-use preferences in infants.
• To compare infant hand-use preferences across different parental handedness patterns.

Main Methods:

• Assessed handedness in 42 infants (6-13 months old) using a validated procedure.
• Measured hand-use preference scores for reaching and object manipulation.
• Grouped infants based on parental handedness: neither parent left-handed, father left-handed, or mother left-handed.

Main Results:

• Infants of left-handed mothers exhibited significantly more left-hand use than infants of left-handed fathers or right-handed parents.
• 64% of infants with left-handed mothers showed a significant left-hand preference.
• No significant left-hand preference was observed in infants from the other parental handedness groups.

Conclusions:

• A distinct maternal effect on infant hand-use preference is evident.
• Left-handed mothers appear to play a crucial role in the development of left-hand preference in their offspring.
• Further research is needed to explore the underlying mechanisms of this maternal influence.