Abstract
Many theories surround the origin of handedness, but the prevailing theory suggests it occurs as a result of exposure to elevated hormone levels in the prenatal environment (Geschwind & Galaburda, 1985), which would result in a relationship between handedness and health conditions; however the majority of studies that have assessed this relationship have focused on university aged or young adult participants. To assess if left-handers have a higher incidence of health conditions later in life, it is essential to use seniors as a target population. In the current study, a convenience sample of seniors from Southern Ontario (n=497), aged 65 and older completed the Waterloo Handedness Questionnaire and a background questionnaire, which included items pertaining to sociodemographic status and medical history. Chi-square analysis revealed that left-handers and inconsistent handers had a higher incidence of certain health conditions. When assessed individually, the following physical health conditions reached significance: fibromyalgia, migraines, deafness, drug allergies, hay fever, psoriasis, cancer, headaches, arthritis, attention deficit disorder, learning disabilities and reading difficulties. Additionally, when males and females were assessed separately, certain conditions that were not associated overall reached significance with separate analyses by gender. Male participants reported more health conditions and were linked with fibromyalgia, migraines, deafness, drug allergies, psoriasis, hay fever, cancer and reading difficulties whereas females were linked with fibromyalgia, migraines, headaches, ADD and learning disabilities. The results will be discussed in light of the Geschwind & Galaburda (1985) theory.Acknowledgments: NSERC