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Type of Measure: According to the empathizing-systemizing theory (E-S theory), there are individual differences in the wiring of the brain that result in two different modes a person may process information: empathizing and systemizing. Empathizing is the drive to identify another person’s emotions and thoughts and to respond to these with an appropriate emotion. Systemizing, however, is the drive to analyse the variables in a system and to derive the underlying rules that govern the behaviour of a system. Systemizing also refers to the drive to construct systems. Systemizing allows you to predict the behaviour of a system, and to control it. Persons with Autism Spectrum Disorders (ASD) are believed to have less ability to empathize and be more systemizing than the general population (Baron-Cohen, Richler, Bisarya, Gurunathan, & Wheelwright, 2003). The Systemizing Quotient (SQ) was then designed to test the E-S theory.

The SQ was designed to be short, easy to complete, and easy to score. The SQ is self administered comprises 60 forced-choice format questions, 40 assessing systemizing and 20 filler (control) items. Approximately half the items were worded to produce a ‘disagree’ and half an ‘agree’, for the systemizing response. This was to avoid a response bias either way. Following this, items were randomized. An individual scores two points if they strongly display a systemizing response and one point if they slightly display a systemizing response. There are 20 filler items (items 2, 3, 8, 9, 10, 14, 16, 17, 21, 22, 27, 36, 39, 46, 47, 50, 52, 54, 58, 59), randomly interspersed throughout the SQ, to distract the participant from a relentless focus on systemizing. These questions are not scored at all.

Items reflect examples from everyday life in which systemizing could be used to varying degrees. The assumption is that a strong systemizer would be drawn to use their systemizing skills across the range of examples more often than a poor systemizer, and would consequently score higher on the SQ.

Target Population: Adults with normal intelligence

Measurement properties and previous use: During intial test development, Baron-Cohen and Wheelwright (2004) assessed differences in systemizing for males and females, and among individuals with and without ASD (N = 278 adults). People with ASD scored significantly lower on the SQ when compared to matched controls. Ling, Burton, Salt, and Muncer (2009) evaluated the psychometric properties of the SQ within a sample of 71 males and 95 females. Participants showed the expected sex difference; the male mean was 30.02 with a SD of 8.6 and the female mean was 21.8 (SD: 8.51). This aggregate score was significantly different (t=6.13, df=164, p<.0005) with an effect size of .96. Males scored significantly higher at p<.05 on 16 of the 40 items. Although females scored higher on 11 items, none of these differences were significant at p<.05 on any item. The item on which females scored most strongly was ‘When I learn a language I become intrigued by its grammatical rules’ (t=−1.78, df=162.91, p=.077).

Reliability analysis showed that the 40-item SQ scale had a reasonable Cronbach’s α of .797. However, eight items had corrected item-total correlations of less than .2, and the removal of three items would have improved the Cronbach’s α to .811. If we continue to remove items until the Cronbach’s alpha would go down we would produce a 30 item scale with an α of .815. This suggests the possibility that a number of the items on the SQ scale are not measuring the same construct (see Ling, Burton, Salt, and Muncer (2009) for complete table).

When examining the SQ’s factor structure, exploratory and confirmatory factors analyses suggested that SQ is best considered as a four-factor 18-item scale, with subscales measuring topography (map reading etc), technicity (an interest in technical information), DIY, and structure (an interest in discovering the structure of things). The taxonomic items in the SQ do not convincingly show a sex difference but there is some evidence that they could form a subscale of their own. Of the four subscales, technicity shows the strongest sex difference and structure the weakest; DIY and topography have the highest loadings on to a higher order factor of Systemizing (see Ling, Burton, Salt, and Muncer (2009) for detailed discussion).

Languages: English

Authors and Citation:

Baron-Cohen, S., Richler, J., Bisarya, D., Gurunathan, N., & Wheelwright, S. (2003). The systemizing quotient: an investigation of adults with Asperger syndrome or high–functioning autism, and normal sex differences. Philosophical Transactions of the Royal Society of London B: Biological Sciences, 358(1430), 361-374.

Baron-Cohen, S., & Wheelwright, S. (2004). The empathy quotient: an investigation of adults with Asperger syndrome or high functioning autism, and normal sex differences. Journal of autism and developmental disorders, 34(2), 163-175.

Ling, J., Burton, T. C., Salt, J. L., & Muncer, S. J. (2009). Psychometric analysis of the systemizing quotient (SQ) scale. British Journal of Psychology, 100(3), 539-552.

Licence: This measures is available in the appendix of the original empirical article and may be used with proper citation.

Link to measure: All test items are located in Appendix A of (Baron-Cohen, Richler, Bisarya, Gurunathan, & Wheelwright, 2003)

Also available:
Systemizing Quotient (SQ) for Adolescents
Systemizing Quotient (SQ) for Children

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