Left handedness and immune disorders.

Area of Science:

• Neuroscience
• Immunology
• Human Biology

Background:

• The Geschwind-Behan hypothesis posits a higher prevalence of immune disorders (IMD) among left-handed individuals.
• Handedness and immune system function are complex traits with potential interactions.

Purpose of the Study:

• To investigate the association between handedness and the prevalence of immune disorders.
• To test the validity of the Geschwind-Behan hypothesis in a large student sample.

Main Methods:

• A sample of 3080 college students self-reported the presence and diagnosis status of various immune disorders.
• Participants also completed the Edinburgh Handedness Inventory to assess laterality.
• Data were analyzed to compare IMD prevalence between left-handed and right-handed individuals, considering sex differences.

Main Results:

• Females reported significantly more IMDs than males.
• No significant difference in IMD prevalence was found between left-handed and right-handed females when considering all response categories.
• A slight increase in IMD was observed in left-handed females when only extreme categories (diagnosed/treated) were considered, but this accounted for minimal variance.
• No handedness effect on IMD was observed in males.
• Laterality quotients were unrelated to IMD reports in both sexes.

Conclusions:

• The study provides no substantial support for the Geschwind-Behan hypothesis.
• While a minor association was noted in females under specific conditions, it explains a negligible amount of variance.
• The relationship between handedness and immune disorders remains inconclusive based on this research.