Left-handers are reputed to be shorter than right-handers. However, previous research has confounded handedness dire ction (left-versus right-handedness) with handedness strength (consistency with which one hand is chosen across a va riety of tasks; consistent-versus inconsistent-handedness). Here, we support a relationship between handedness strength, but not direction, and stature, with increasing inconsistent-handedness associated with increasing self-reported height.
Left-handers are reputed to be shorter than right-handers [1-4]. However, previous work has assessed handedness via archival records of sports figures, using one activity (e.g. batting) to classify handedness, thereby confounding handedness direction (leftversus right-handedness) with handedness strength (consistency with which one hand is chosen across a variety of tasks; consistentversus inconsistent-handedness). Handedness direction and strength both contribute to between-subject variation in cognitive/physiological measures [
height was assessed. Here, in this Short Report, we support a relationship between handedness strength, but not direction, and stature.
As part of a larger protocol, participants (N = 141) completed written consent (the study was approved via the MSU Institutional Review Board and the Army Human Research Protection Office), self-reported their height, and filled out the Edinburgh Handedness Inventory (EHI). The EHI consists of 10 activities that participants rate as performing with the right or left hand “always”, “usually”, or having no hand preference. Graduated scoring results in a range from −100 (perfectly consistent-lefthandedness) to +100 (perfectly consistent-right-handedness).
Handedness Direction: Unpaired t-test comparing height (cm) between left- (n = 12; EHI score equal/below 0) and right- (n = 129; EHI score above 0) handers was nonsignificant (p > 0.20). Height also did not correlate with EHI overall or as a function of gender (p > 0.30). See
Handedness Strength: Height negatively correlated with absolute value of EHI (|EHI|), r(139) = −0.22, p < 0.01, a measure that collapses across handedness direction, while maintaining handedness strength. See
Handedness Direction and Strength: Handedness was trichotomized into consistent-left-(CLH), right-(CRH), and inconsistent-handed (ICH) groups via the median of the |EHI| score (|80|) [see 5]. Scores +80 and above were CRH (n = 71), scores −80 and below were CLH (n = 7), and scores +75 to −75 were ICH (n = 63); A one-way Analysis of Variance revealed an effect (f(2,138) = 3.0, p = 0.05); ICH (x = 168.41, sd = 11.47) were taller (by 3.72 cm) than CRH (x = 164.69, sd = 8.66; Fisher’s PLSD, p < 0.05), and marginally (Fisher’s PLSD p = 0.10) taller (by 6.58 cm) than CLH (x = 161.83, sd = 9.92). See
Handedness strength (measured via the absolute value of
shared mediation by in utero hormonal factors (e.g. testosterone), a suggestion supported by the fact that men, not women, demonstrated this relationship. Leftand right-handers did not differ from each other, nor did consistent-rightand consistent-left-handers. Inconsistenthanders however were taller than both consistentlyhanded groups, and significantly so relative to consistentright-handers. Limitations of the present finding are based primarily on the limited number of participants, the need for additional testing of men and women, and the reliance on self-reported height. Nevertheless, the results call into question previously analyzed archival data based on single measures of handedness. The results here further support that non-right-handedness is not a homogenous trait that can be determined by performance on one activity [