on sex and suicide bombing

Please note this post was edited (below) on 23 May 2011

David Lawson, Kesson Magid and I have just published On Sex and Suicide Bombing: An evaluation of Kanazawa’s ‘Evolutionary Psychological Imagination’. This is a critique of Satoshi Kanazawa’s 2007 paper: “The Evolutionary Psychological Imagination: Why You Can’t Get a Date on a Saturday Night and Why Most Suicide Bombers are Muslim.”

Many objections to evolutionary psychology are ideological or political. This is not the case in our paper: nothing makes me (and my co-authors) froth at the mouth more than bad science. We say:

The beauty of the scientific method is that it allows us to ask, and sometimes answer, tough questions.
Addressing the tough questions without the transparency afforded by the scientific method is not brave: it is simply cavalier.

Kanazawa’s paper is full of bad science. We are not the first to criticise him on such grounds, but it bears repeating that when there are controversial and sensitive issues at stake, we beholden to demand a high standard of scholarship and science.

EDIT 23 May 2011

In the light of another piece of “science” by Kanazawa, reported on his blog, I have decided to add to this post a list of the published academic responses to Kanazawa’s work. It really saddens me that someone who pushes an agenda to carry out controversial investigations cannot pair that agenda with quality science. As said above, with academic freedom comes responsibility.

This list was compiled with the help of colleagues. Please let me know of any additions or corrections. At last count, the 20 listed papers involved 56 separate authors.

A list of recent papers* criticising the poor scientific standards of Kanazawa’s research:

1. Penke, L., Borsboom, D., Johnson, W., Kievit, R. A., Ploeger, A., & Wicherts, J. M. (in press). Evolutionary psychology and intelligence research cannot be integrated the way Kanazawa (2010) suggests. American Psychologist.**
2. Wicherts, J.W., Borsboom, D, Dolan, C.V. (2010) Why national IQs do not support evolutionary theories of intelligence. Personality and Individual Differences 48, 91-96
3. Gelman A. & Weakliem D. (2009). Of beauty, sex and power: statistical challenges in estimating small effects. American Scientist 97, 310–316.
4. Denny, K. (2009). On a dubious theory of cross-country differences in intelligence. Journal of Evolutionary Psychology 7: 341-346
5. Lawson, D.W., Jordan, F.M. & Magid, K. (2008). On sex and suicide bombing: an evaluation of Kanazawa’s ‘Evolutionary Psychological Imagination’. Journal of Evolutionary Psychology 6, 73-84.
6. Rickard I.J. (2008) Kanazawa’s ‘Generarized Trivers-Willard hypothesis’ and the heritability of offspring sex ratio. Journal of Evolutionary Psychology 4, 255-260.
7. Denny, K. (2008) Big and tall parents do not have more sons. Journal of Theoretical Biology 250(4): 752-3
8. Denny, K. (2008) Beauty and intelligence may – or may not – be related. Intelligence 36(6): 616-618
9. Girotto, V. & Tentori, K. (2008) Is domain general thinking a domain specific adaptation? Mind and Society 7(2) 167-75
10. Gelman A. (2007). Letter to the editors regarding some papers of Dr. Satoshi Kanazawa. Journal of Theoretical Biology 245: 597-599.
11. Dickins, T.E., Sear, R. & Wells, A.J. (2007) Mind the gap(s)…in theory, method and data: Re-examining Kanazawa (2006) British Journal of Health Psychology 12: 167-178
12. Der, G. (2007). IQ and the health of nations: Some critical comments on Kanazawa (2006). British Journal of Health Psychology 12: 315-321
13. Alemayehu, D. & Sineshaw, T. (2007). A commentary on Satoshi Kanazawa’s study of intelligence and health. British Journal of Health Psychology 12: 185-190.
14. Wilkinson, R.G. & Pickett K.E. (2007). Economic development and inequality affect IQ. A response to Kanazawa. British Journal of Health Psychology 12: 161-166.
15. Ellison, G.T.H. (2007). Health, wealth and IQ in sub-Saharan Africa: Challenges facing the Savanna Principle as an explanation for global inequalities in health. British Journal of Health Psychology 12: 191-227
16. Marks, D.F. (2007). Literacy not intelligence moderates the relationships between economic development, income inequality and health. British Journal of Health Psychology 12: 179-184
17. Miller, G.F. (2006). Asian creativity: A response to Satoshi Kanazawa. Evolutionary Psychology 4: 129-137.
18. Volscho, T.W. (2005) Money and sex, the illusory universal sex difference: comment on Kanazawa. Sociological Quarterly 46, 719-36
19. Freese, J.. 2003. “Imaginary Imaginary Friends?: Television Viewing and Satisfaction with Friendships.”  Evolution and Human Behavior 24: 65-69.
20. Freese, J. and Powell, B. (2001) Making love out of nothing at all? Null findings and the Trivers-Willard hypothesis. American Journal of Sociology 106, 1776-89

* – As far as we are aware Kanazawa has never taken the opportunity to response to these criticisms in print.

** this was originally co-authored by Jens B Asendorpf, Timothy C  Bates, David M Buss, Daniel Cervone, Ian J Deary, Jaap J A Denissen, Conor V Dolan, Willem E Frankenhuis, Wolfgang Gaissmaier, Steven W Gangestad, David C Geary, Vittorio Girotto, Samuel D Gosling, Linda S Gottfredson, Rex E Jung, Matthew C Keller, Michelle Luciano, Richard McElreath, Geoffrey F Miller, Daniel Nettle, Aljoscha Neubauer, Steven Pinker, Richard D Roberts, Frank M Spinath, Marieke E Timmerman, Francis Tuerlinckx, Han L J van der Maas, Oliver Wilhelm, Alexander Weiss but their names were removed on demand of the editorial board.