Attempts to switch the writing hand: relationships to age and side of hand preference

The recent suggestion that left-handedness is a mortality risk factor has prompted extensive media attention and has renewed research interest in generational differences in hand preference incidence and training. It is argued that differential generational training effects (the modification hypothesis), rather than decreased survival fitness (the elimination hypothesis), account for the lower numbers of individuals classified as left-handers in contemporary samples over the age of 60 years. A total of 633 individuals (aged 13-83 years) were queried about attempts to switch hand preference. Forty-one (6.5%) described efforts to shift preference in the rightward direction; of these, 21 (3.3%) reported attempted rightward writing hand shifts. The percentage of older adult left-handers, who reported right shifts in writing, was greater than the percentage of younger left-handers who described such attempts. Comparisons between the group reporting right shifts and those reporting no shift experiences suggested that the age-related decrease in leftward preference was specific to a decrease in the incidence of left-hand writing among older adults.