Tourette Syndrome and IQ: Tics, Neurodevelopment, and Intelligence
Tourette Syndrome (TS) is a neurodevelopmental disorder characterized by multiple motor tics and at least one vocal tic, present for more than one year and typically beginning in childhood (mean age of onset 5–7 years). It affects approximately 1% of school-age children and is 3–4 times more common in males than females. TS is frequently mischaracterized by the media as primarily involving coprolalia (involuntary swearing), which actually occurs in fewer than 15% of cases. The vast majority of TS consists of non-disruptive motor tics (eye blinking, head nodding, facial grimacing) and vocal tics (sniffing, throat clearing, humming). Critically, TS is not associated with reduced intelligence — people with TS span the full range of cognitive ability. However, the co-occurring conditions that accompany TS — which are present in the majority of affected individuals — substantially affect cognitive performance and IQ testing.
How Tourette Syndrome Affects IQ Test Performance
Tourette Syndrome alone — without co-occurring conditions — has minimal direct impact on IQ test performance. Research finds that individuals with 'pure TS' (TS without ADHD, OCD, or learning disabilities) have full-scale IQ scores indistinguishable from the general population. However, pure TS is the minority: approximately 50–60% of individuals with TS have co-occurring ADHD, 40–50% have OCD, and 20–30% have a learning disability — each of which carries its own cognitive profile and IQ test impact. When these co-occurring conditions are accounted for, the common finding of lower mean IQ in TS samples largely disappears. The individual impact on IQ testing therefore depends almost entirely on which co-occurring conditions are present. The tics themselves can briefly disrupt performance during assessment when they occur during a critical task, but experienced examiners can accommodate tic-related interruptions by allowing the subtest to pause and resume.
What the Research Shows
A landmark meta-analysis by Sukhodolsky and colleagues in 2017 in the Journal of Child Psychology and Psychiatry found that when ADHD comorbidity was statistically controlled, individuals with Tourette Syndrome showed no significant IQ differences from typically developing controls — confirming that the cognitive profile in TS is driven by co-occurring conditions rather than TS itself. Research by the Tourette Association of America has documented that the educational and psychosocial challenges of TS are largely mediated by ADHD and OCD co-occurrence, with pure TS showing minimal academic impact. Neuroimaging research has found differences in cortico-striato-thalamo-cortical (CSTC) circuits in TS, the same circuits implicated in ADHD and OCD — providing a neurobiological explanation for the high co-occurrence rates and shared cognitive profiles. A 2020 study in the Journal of Neurology found that individuals with TS who achieved good tic suppression — either pharmacologically or through behavioral therapy — showed improved performance on processing speed and attention tasks, suggesting that active tic suppression consumes cognitive resources that, when freed, become available for other cognitive work.
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Frequently Asked Questions
Does Tourette Syndrome lower IQ?
Tourette Syndrome itself does not lower IQ. Studies find that people with pure TS (without ADHD or OCD) have IQ scores indistinguishable from the general population. The lower average IQ scores sometimes reported in TS research reflect the high rates of co-occurring ADHD and OCD in TS samples, not the tic disorder itself. If a person with TS has lower IQ test scores, the contributing factors are almost certainly the co-occurring conditions, not the tics.
Do tics affect IQ test performance?
Tics can briefly disrupt specific test items if they occur at critical moments, but experienced examiners pause and restart affected items, minimizing the impact. More significant are the suppression demands of tics: many individuals with TS actively suppress their tics during formal assessment (as they often do in public situations), which consumes cognitive resources and can reduce processing speed and working memory performance. This suppression-related cognitive load is modest but real, and examiners familiar with TS should account for it in their interpretation.
Can people with Tourette Syndrome be gifted?
Yes. Tourette Syndrome occurs across the full range of intelligence, and several studies have noted that TS may be somewhat over-represented in high-IQ populations — possibly reflecting the shared genetic architecture between TS and ADHD, which itself shows associations with creativity and divergent thinking. Many highly accomplished individuals have TS, including athletes, musicians, surgeons, and academics. The stereotype of TS as a disabling condition is strongly at odds with the actual functioning of many people with the disorder, particularly when tics are well-managed.
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MyIQScores Editorial Team
Researchers in cognitive psychology, psychometrics & educational science
Last updated
May 10, 2026
All content on MyIQScores is reviewed for scientific accuracy against peer-reviewed research in cognitive psychology and psychometrics. Our editorial team cross-references each article with published literature before publication and updates pages whenever new research warrants a revision.