Can the declining prevalence of left-handedness with age be due to smoking?

The objective of this study was to assess whether smoking habits can explain the decline in left-handedness prevalence with age. Subjects participating in a population-based survey (n = 3,071) in Geneva, Switzerland, completed a questionnaire on innate hand preference, current hand preference for writing and smoking habits. The prevalence of innate left-handedness in the Geneva population was 9.4% in men and 7.4% in women. There was no association between smoking and left-handedness. It is concluded that smoking is not associated with hand preference and is an unlikely cause of overmortality in left-handed subjects.