Prevalence of Red Hair and Left-Handedness
Red hair occurs in roughly 1 to 2 percent of the global population, while left-handedness affects about 10 percent. Both traits are more common in people of Northern European descent. Exact overlap is not precisely known, but studies suggest left-handedness may be slightly more frequent among redheads than in the general population.
Genetic Factors
Red hair is strongly linked to variants in the MC1R gene on chromosome 16. Left-handedness is polygenic, with multiple genes contributing, including those involved in brain asymmetry. Research indicates some shared genetic regions may influence both hair color and handedness, though the relationship remains complex and not fully understood.
Traits and Research Findings
Some studies report that redheads may have different pain thresholds and responses to anesthesia. Left-handed individuals often show atypical lateralization of brain function. A large-scale study found a modest statistical association between red hair and left-handedness, but the link is not deterministic and most redheads are right-handed.
For more on human genetic variation, see NCBI: Human genetic variation.
