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Philos Trans R Soc Lond B Biol Sci. Feb 28, 2003; 358(1430): 361–374.
PMCID: PMC1693117

The systemizing quotient: an investigation of adults with Asperger syndrome or high-functioning autism, and normal sex differences.

Abstract

Systemizing is the drive to analyse systems or construct systems. A recent model of psychological sex differences suggests that this is a major dimension in which the sexes differ, with males being more drawn to systemize than females. Currently, there are no self-report measures to assess this important dimension. A second major dimension of sex differences is empathizing (the drive to identify mental states and respond to these with an appropriate emotion). Previous studies find females score higher on empathy measures. We report a new self-report questionnaire, the Systemizing Quotient (SQ), for use with adults of normal intelligence. It contains 40 systemizing items and 20 control items. On each systemizing item, a person can score 2, 1 or 0, so the SQ has a maximum score of 80 and a minimum of zero. In Study 1, we measured the SQ of n = 278 adults (114 males, 164 females) from a general population, to test for predicted sex differences (male superiority) in systemizing. All subjects were also given the Empathy Quotient (EQ) to test if previous reports of female superiority would be replicated. In Study 2 we employed the SQ and the EQ with n = 47 adults (33 males, 14 females) with Asperger syndrome (AS) or high-functioning autism (HFA), who are predicted to be either normal or superior at systemizing, but impaired at empathizing. Their scores were compared with n = 47 matched adults from the general population in Study 1. In Study 1, as predicted, normal adult males scored significantly higher than females on the SQ and significantly lower on the EQ. In Study 2, again as predicted, adults with AS/HFA scored significantly higher on the SQ than matched controls, and significantly lower on the EQ than matched controls. The SQ reveals both a sex difference in systemizing in the general population and an unusually strong drive to systemize in AS/HFA. These results are discussed in relation to two linked theories: the 'empathizing-systemizing' (E-S) theory of sex differences and the extreme male brain (EMB) theory of autism.

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Selected References

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  • Bailey A, Le Couteur A, Gottesman I, Bolton P, Simonoff E, Yuzda E, Rutter M. Autism as a strongly genetic disorder: evidence from a British twin study. Psychol Med. 1995 Jan;25(1):63–77. [PubMed]
  • Baron-Cohen Simon. The extreme male brain theory of autism. Trends Cogn Sci. 2002 Jun 1;6(6):248–254. [PubMed]
  • Baron-Cohen S, Jolliffe T, Mortimore C, Robertson M. Another advanced test of theory of mind: evidence from very high functioning adults with autism or asperger syndrome. J Child Psychol Psychiatry. 1997 Oct;38(7):813–822. [PubMed]
  • Baron-Cohen S, O'Riordan M, Stone V, Jones R, Plaisted K. Recognition of faux pas by normally developing children and children with Asperger syndrome or high-functioning autism. J Autism Dev Disord. 1999 Oct;29(5):407–418. [PubMed]
  • Baron-Cohen S, Ring HA, Wheelwright S, Bullmore ET, Brammer MJ, Simmons A, Williams SC. Social intelligence in the normal and autistic brain: an fMRI study. Eur J Neurosci. 1999 Jun;11(6):1891–1898. [PubMed]
  • Baron-Cohen S, Ring HA, Bullmore ET, Wheelwright S, Ashwin C, Williams SC. The amygdala theory of autism. Neurosci Biobehav Rev. 2000 May;24(3):355–364. [PubMed]
  • Baron-Cohen S, Wheelwright S, Skinner R, Martin J, Clubley E. The autism-spectrum quotient (AQ): evidence from Asperger syndrome/high-functioning autism, males and females, scientists and mathematicians. J Autism Dev Disord. 2001 Feb;31(1):5–17. [PubMed]
  • Folstein S, Rutter M. Infantile autism: a genetic study of 21 twin pairs. J Child Psychol Psychiatry. 1977 Sep;18(4):297–321. [PubMed]
  • Folstein SE, Rutter ML. Autism: familial aggregation and genetic implications. J Autism Dev Disord. 1988 Mar;18(1):3–30. [PubMed]
  • Frith CD, Frith U. Interacting minds--a biological basis. Science. 1999 Nov 26;286(5445):1692–1695. [PubMed]
  • Geschwind N, Galaburda AM. Cerebral lateralization. Biological mechanisms, associations, and pathology: I. A hypothesis and a program for research. Arch Neurol. 1985 May;42(5):428–459. [PubMed]
  • Happé FG. Studying weak central coherence at low levels: children with autism do not succumb to visual illusions. A research note. J Child Psychol Psychiatry. 1996 Oct;37(7):873–877. [PubMed]
  • Hoffman ML. Sex differences in empathy and related behaviors. Psychol Bull. 1977 Jul;84(4):712–722. [PubMed]
  • Jolliffe T, Baron-Cohen S. Are people with autism and Asperger syndrome faster than normal on the Embedded Figures Test? J Child Psychol Psychiatry. 1997 Jul;38(5):527–534. [PubMed]
  • Klin A, Volkmar FR, Sparrow SS, Cicchetti DV, Rourke BP. Validity and neuropsychological characterization of Asperger syndrome: convergence with nonverbal learning disabilities syndrome. J Child Psychol Psychiatry. 1995 Oct;36(7):1127–1140. [PubMed]
  • Frith U, Morton J, Leslie AM. The cognitive basis of a biological disorder: autism. Trends Neurosci. 1991 Oct;14(10):433–438. [PubMed]
  • Ozonoff S, Strayer DL, McMahon WM, Filloux F. Executive function abilities in autism and Tourette syndrome: an information processing approach. J Child Psychol Psychiatry. 1994 Sep;35(6):1015–1032. [PubMed]
  • Shah A, Frith U. An islet of ability in autistic children: a research note. J Child Psychol Psychiatry. 1983 Oct;24(4):613–620. [PubMed]
  • Wing L. Asperger's syndrome: a clinical account. Psychol Med. 1981 Feb;11(1):115–129. [PubMed]

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