Hand preference and age in the United States

Area of Science:

• Neuroscience
• Human Biology
• Psychology

Background:

• Hand preference, or handedness, is a complex trait with varying prevalence across populations.
• Previous research suggested a decline in left-handedness with advancing age, but detailed analysis of specific subtypes was limited.

Purpose of the Study:

• To investigate the prevalence of left-handedness and mixed-handedness in a large U.S. population across different age groups.
• To examine the concordance of hand preference for writing and throwing among left-handed individuals.
• To confirm and elaborate on age-related changes in sinistrality.

Main Methods:

• A large-scale survey of 1,177,507 U.S. men and women aged 10-86.
• Inclusion of questions on hand preference for writing and throwing.
• Statistical analysis of prevalence rates based on age and hand preference patterns.

Main Results:

• Prevalence of individuals with any left motoric bias decreased with advancing age.
• Among left-handed individuals, writing and throwing concordance was significantly higher than mixed-handedness patterns.
• Distinct and stable prevalence rates for sinistral subpopulations were observed before age 50, with changes noted thereafter.

Conclusions:

• Confirms a decrease in overall left-handedness (sinistrality) with age.
• Highlights that age-specific rates for mixed-handedness and pure left-handedness are distinct.
• Suggests that hypotheses on age-related changes in sinistrality need to consider these distinct patterns.