Evidence of a right-shift factor affecting infant hand-use preferences from 7 to 11 months of age as revealed by latent class analysis

Area of Science:

• Developmental Psychology
• Neuroscience
• Human Motor Control

Background:

• Hand preference, or handedness, is a fundamental human trait with origins in early development.
• Understanding infant hand-use is crucial for tracing the developmental trajectory of handedness.
• Previous research has explored handedness in children and adults, but early precursors require further investigation.

Purpose of the Study:

• To investigate the emergence and stability of hand-use preferences in infants.
• To identify developmental precursors of adult handedness in early infancy.
• To examine the influence of classification procedures on the assessment of infant handedness.

Main Methods:

• Assessed hand-use preferences for object apprehension in 154 infants at 7, 9, and 11 months of age.
• Employed two classification procedures with varying Type I error rates to determine infant preference (right, left, no preference).
• Utilized two- and three-group latent class analysis models to analyze handedness data.

Main Results:

• Demonstrated the significance of using classification procedures with low Type I error rates for accurate handedness assessment.
• Identified evidence of a right-shift factor in infant hand-use, mirroring patterns seen in older children and adults.
• Confirmed that infant hand-use preferences for object apprehension are a likely developmental precursor to adult handedness.

Conclusions:

• Infant hand-use preference is a critical developmental precursor to adult handedness.
• The observed right-shift factor in infants suggests an early biological basis for handedness.
• Findings contribute to understanding the evolution of human abilities and the role of social influences in development.