Handedness, criminality, and sexual offending
Introduction
Nonright-handedness (NRH) is not per se pathological (e.g. [5]), but most cerebral lateralization researchers argue that elevated NRH in clinical groups can result from developmental/central nervous system (CNS) disorders (e.g. [2], [8], [29], [32]; but see [1], [25]).
Evidence, therefore, that people with a history of criminality have elevated NRH may give support for the theory that these behaviors result, in part, from developmental/CNS abnormalities. The evidence supporting such a relationship is mixed. Reviewing early studies, Porac and Coren [27] noted an association between NRH and criminality. Three recent studies also support such a relationship [11], [14], [19], but some recent studies have been contradictory [12], [20], [33], with at least two finding evidence of less NRH in men with a criminal history [20], [26]. More data on a large sample may help clarify this association. Moreover, few studies have addressed how other variables, such as education, may relate to a putative handedness/criminality relationship. For example, might NRH be related to criminality in part because those with NRH are more likely to have educational difficulties, which, in turn, creates impaired societal functioning (e.g. ‘acting out’), or do NRH and educational difficulties have independent effects on criminality?
One antisocial group that is a good candidate for increased NRH resulting from developmental/CNS abnormalities is sex offenders because many sex offenders may have developmental/CNS abnormalities (see [24]). Perhaps the strongest evidence for such abnormalities has been found in pedophiles, offenders with erotic preferences for pre-pubescents. This evidence includes the finding that pedophiles show hypersecretion of luteinizing hormone under gonadotropin-releasing hormone stimulation [3], [15]. Using CT scans, pedophiles have also been found to have less dense right frontal areas of the brain [21] and the smallest left frontal and temporal areas of the brain and the greatest asymmetry [31] relative to other men. Neuropsychological testing has confirmed that elevated left-hemispheric impairment may occur in pedophiles (e.g. [22]). Interestingly, such left hemisphere damage, if it proves reliable, suggests elevated NRH should be found in pedophiles because left hemisphere damage has been linked to elevated NRH (e.g. [29]).
I am not aware of research examining if sex offenders (e.g. pedophiles) have elevated NRH. However, one very large sample with information on handedness, criminality, and sex offending comes from the Kinsey Institute [17], [23]. With data available on over 8000 men, including 1400 sex offenders [16], this sample provides a rare opportunity to conduct powerful tests of the relations among handedness, criminality, and sexual offending. These tests are the focus of the present study. If, for example, men with a history of criminality and/or sexual offending have increased NRH relative to controls, then this finding may provide additional evidence that CNS abnormalities affect criminality and/or atypical sexual preferences.
Section snippets
Subjects
From 1938 to 1963, 17 502 case histories were recorded by the Kinsey Institute for Sex, Gender and Reproduction, using the interview schedule devised by its founder A.C. Kinsey [17]. The Kinsey files contain 2498 white men with a history of criminality. These men had been arrested and/or convicted of at least one misdemeanour or felony. Type of (nonsexual) offence was not coded in the original files. Of these men, 1410 had a conviction for a sexual offence, most of whom (1283) were classified
Results
Men with a criminal history (both sex and nonsex offenders) were 85.8% right-handed (valid n=2086), whereas controls were 88.5% right-handed (valid n=4706), a significant difference using a 2 (i.e. nonright by right-handed) by 2 (i.e. offenders by controls) contingency table (χ2 (1, N=6792)=10.38, P=0.001). Similar results occurred comparing right-handers to ambiguous/mixed (i.e. ‘ambidextrous’) handers (offenders=4.7%; controls=3.5%) and right-handers to left-handers (offenders=9.6%;
Discussion
Results indicated that men with a history of criminality and/or sexual offending (e.g. pedophiles) have elevated NRH. Although the effects were small, it should be noted that a 5% difference means about a 30% change in NRH (e.g. 15.7% in pedophiles vs. 11.5% in controls). In addition, large differences in handedness rates are not expected, given power analyses suggesting that finding a handedness difference between groups may be low even with large samples (e.g. [9]). This is in part because
Acknowledgements
The author wishes to thank the Kinsey Institute for Research in Sex, Gender, and Reproduction for allowing access to these data. In particular, I would like to thank Dr. Bancroft (Director of the Institute), and Thomas Albright for assistance with conducting the analyses. I would also like to thank Drs. Ray Blanchard, Martin Lalumiere, Carolyn Hafer, Sid Segalowitz and several anonymous reviewers for suggestions at various stages of this research.
References (33)
- et al.
Handedness and birth stress
Neuropsychologia
(1973) Measuring handedness with questionnaires
Neuropsychologia
(1977)Left- and mixed-handedness and criminality: explanations for a probable relationship
- et al.
Hand preference and age in the United States
Neuropsychologia
(1992) A factor analysis of self-reported handedness
Neuropsychologia
(1978)Pathological left-handedness: an exploratory model
Cortex
(1972)Left, right, hand, and brain: the right shift theory
(1985)- et al.
Sex hormones in pedophiles, I: baseline values of six hormones, II: the gonadatropin-releasing hormone test
Annals of Sex Research
(1988) - et al.
Handedness in the mentally handicapped
Developmental Medicine and Child Neurology
(1985) Handedness and developmental disorders
(1990)
Handedness in homosexual and heterosexual men in the Kinsey interview data
Archives of Sexual Behavior
The left-hander syndrome. The causes and consequences of left-handedness
Failure to find statistical significance in left-handedness and pathology studies: a forgotten consideration
Bulletin of the Psychonomic Society
Delinquency, sidedness, and sex
Journal of General Psychology
Is there an association between lateral preference and delinquent behavior?
Journal of Abnormal Psychology
Sex offenses against female children perpetrated by men who are not pedophiles
Journal of Sex Research
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