Title: Handedness and Religious Beliefs
Authors: Douglas Degelman, Denée Heinrichs, and Hisashi Ishitobi
Affiliation: Vanguard University of Southern California
Introduction: Niebauer, Christman, Reid, and Garvey (2004) have found that strongly-handed individuals, whose two cerebral hemispheres may interact less than mixed-handed individuals, were more likely than mixed-handed individuals to believe in Biblical creationist accounts of human origins. Niebauer et al. argue that the two hemispheres are involved differently in how individuals maintain and update their beliefs, with the left hemisphere more involved in maintaining consistency of beliefs and the right hemisphere more involved in monitoring beliefs and registering inconsistencies. If interhemispheric communication underlies the updating of beliefs, and if strongly-handed individuals evidence less interhemispheric interaction than mixed-handed individuals, then strongly-handed individuals may be more likely than mixed-handed individuals to maintain religious beliefs that have been uncritically held.
Hypothesis: The extent to which individuals believe in divine intervention will be associated with degree of handedness, with more strongly-handed individuals believing in divine intervention to a greater extent than mixed-handed individuals.
Participants: From June 6, 2002 through January 27, 2004, 588 respondents (210 men, 378 women) completed an online survey on “Handedness and Religious Beliefs” linked to either Hanover College’s “Psychological Research on the Net” page (http://psych.hanover.edu/research/exponnet.html) or Vanguard University’s AmoebaWeb “Research Participation” page (http://www.vanguard.edu/psychology/amoebaweb/research-participation/). Of the 588 respondents, 492 (83.67 %) were identified as right-handed by the Waterloo Handedness Questionnaire (Steenhuis & Bryden, 1989) and 96 (16.33%) were identified as left-handed. Participants reported ages ranged from 18 – 71 (M = 27.92, SD = 10.49, Mdn = 23). The reported ages of men (M = 28.71, SD = 10.84) and women (M = 27.48, SD = 10.28) were not significantly different, t (586) = 1.372, p = .171. Reported ages of left-handed respondents (M = 30.49, SD = 11.45) were significantly higher than those of right-handed respondents (M = 27.42, SD = 10.23). Reported ages of participants did not significantly differ across the different categories of attendance at religious services, F (5, 579) = .741, p = .593.
Procedure: Participants who clicked a link to an online study of “Handedness and Religious Belief and Practice” from either of the Web sites were presented with an “Information Sheet” that described the purpose and procedures of the online study. Clicking a link from the Information Sheet to the online survey was taken to reflect informed consent. Participants completed the Waterloo Handedness Questionnaire (WHQ) and the Belief in Divine Intervention Scale (Degelman & Lynn, 1995). The WHQ asks respondents to indicate for each of 32 questions which hand is used to perform the described activity (right always, left always, right usually, left usually, both equally). Scores can range from -64 (completely left-handed) to +64 (completely right-handed). Absolute values of the WHQ (AWHQ) provided a measure of the degree of handedness (possible range of 0 – 64, with lower numbers reflecting mixed handedness and higher numbers reflecting more strongly-handed individuals). Scale items were completed by use of pull-down menus that revealed all possible responses to each item. After completing the online survey, participants clicked a “Submit” button to complete the process and submit the data.
The six-item Belief in Divine Intervention Scale (BDISS) is designed to assess the extent to which people believe in divine intervention, including God’s physical healing of humans, direct communication with humans, and intervention in conditions of nature. Participants indicated their level of agreement or disagreement with each of the six items using a 6-point rating scale for all items (Levenson, 1974). The scale options for each item ranged from -3 (strongly disagree) to +3 (strongly agree). The possible range of scores for the BDISS is 0 – 36, with higher scores reflecting higher levels of belief in divine intervention. The BDISS has been reported (Degelman & Lynn, 1995) to be unidimensional and to have a high level of internal consistency (coefficient alpha = .910).< /FONT >
In addition to completing the two scales, participants were asked their age, gender, and frequency of attendance at religious services, for which there were six options, ranging from “never” to “less than once per month” to “once per month” to “less than once per week but more than once per month” to “once per week” to “more than once per week.”
Preliminary Analyses: We analyzed the data obtained from all respondents who completed the two scales described above, who reported their gender, and whose reported age was at least 18.
As expected, BDIS scores differed significantly across the different categories of attendance at religious services, F (5, 579) = 121.85, p = .000. Mean BDIS scores ranged from 18.67 (SD = 17.01) for those who reported never attending religious services to 31.59 (SD = 6.30) for those who reported attending religious services more than once per week. Also as expected, BDIS scores of women (M = 19.64, SD = 12.76) were significantly higher than BDIS scores of men (M = 16.21, SD = 13.58), t (586) = -3.049, p = .002. No significant association was found between sex and frequency of attendance at religious services, c2 (df = 5, n = 585) = 9.63, p = .086.
Degree of handedness (AWHQ) did not differ significantly between men (M = 35.79, SD = 12.63) and women (M = 37.77, SD = 13.03), t (586) = -1.786, p = .075. BDIS scores of left-handed individuals (M = 17.73, SD = 13.26) and right-handed individuals (M = 18.55, SD = 13.14) did not differ significantly, t (586) = .557, p = .578.
Handedness and Belief in Divine Intervention: Overall, correlations between Belief in Divine Intervention and degree of handedness were close to zero and statistically nonsignificant (p > .10). The correlation between BDIS and AWHQ was -.017 (r2 = .0003). For respondents who reported having an immediate relative who is left-handed, the correlation between BDIS and AWHQ was +.081 (r2 = .0066). For those who reported not having an immediate relative who is left-handed, the correlation between BDIS and AWHQ was -.048 (r2 = .0023).
BDIS scores of strongly-handed individuals (AWHQ scores of 50-64) and mixed-handed individuals (AWHQ scores of 1-24) did not differ significantly, t (188) = .434, p = .665. The mean BDIS score for strongly-handed individuals was 18.23 (SD = 13.38), and the mean BDIS score for mixed-handed individuals was 19.06 (SD = 13.01).
Conclusions: No evidence was found of a significant association between degree of handedness and belief in divine intervention in this online study of 588 respondents. These results may call into question the assumption of interhemispheric communication underlying the updating of beliefs or the finding that strongly-handed individuals evidence less interhemispheric interaction than mixed-handed individuals.
If interhemispheric communication does underlie the updating of beliefs, and if strongly-handed individuals do evidence less interhemispheric interaction than mixed-handed individuals, then the lack of a significant association between degree of handedness and belief in divine intervention may reflect unique dynamics related to the belief in divine interaction. Perhaps the predicted association between degree of handedness and beliefs is limited to uncritically accepted beliefs; belief in divine intervention may reflect a more thoroughly examined belief.
In spite of a higher proportion of left-handed participants in the study than in the general population, a lack of independent confirmation of the identity of the respondents, and an inability to rule out the possibility of individuals participating in the online research more than once, the size of the sample, the 18-month duration of the study, and the use of two university Web sites to invite research participation resulted in a relatively broad-based sample of Internet-using adults interested in psychological research.
Degelman, D. & Lynn, D. (1995). The development and preliminary validation of the Belief in Divine Intervention Scale. Journal of Psychology and Theology, 23,37-44.
Niebauer, C. L., Christman, S. D., Reid, S. A., & Garvey, K. J. (2004). Interhemispheric interaction and beliefs on our origin: Degree of handedness predicts beliefs in creationism versus evolution. Laterality: Asymmetries of Body, Brain & Cognition, 9, 433-447.
Steenhuis, R. E., & Bryden, M. P. (1989). Different dimensions of hand preference that relate to skilled and unskilled activities. Cortex, 25, 289-304.