Understanding the CATI
What is the CATI?
The Comprehensive Autistic Trait Inventory (CATI) is a questionnaire designed to measure autistic traits in adults. It consists of 42 statements covering a broad range of characteristics commonly associated with autism, including social interactions, communication, sensory sensitivity, social camouflage, self-regulatory behaviours, and cognitive flexibility.
The CATI was developed by researchers at The University of Western Australia to reflect current understanding of autism and to provide researchers with a modern, comprehensive measure of autistic traits. It is now used by researchers around the world in studies of autism and the broader autism phenotype.
What can the CATI be used for?
The CATI is designed primarily for research purposes, where it is used to measure autistic traits in adults. Researchers may use the total score to provide an overall measure of autistic traits or examine the six subscale scores to better understand specific areas of functioning.
Many people also choose to complete the CATI out of personal interest to better understand their own pattern of autistic traits. While the CATI can provide useful information about these traits, it is not a diagnostic assessment and should not be used to determine whether someone is autistic.
What do my CATI scores mean?
Your CATI results provide a summary of the extent to which your responses resemble traits commonly associated with autism. Higher scores indicate a greater endorsement of autistic traits, while lower scores indicate fewer autistic traits.
In addition to your total score, the CATI provides scores for six subscales. These can help identify which particular traits contribute most to your overall score. For example, two people may have similar total scores but very different patterns of strengths and challenges across the six trait domains.
The CATI measures traits that exist on a continuum throughout the general population. There is no single score that determines whether someone is autistic.
I scored above the recommended threshold. Does this mean I am autistic?
No. Although people with scores above the recommended threshold are more likely to be autistic than those with lower scores, the CATI cannot determine whether someone is autistic.
In our current research, a total score of approximately 148 provided the best balance between identifying autistic and non-autistic adults. However, many autistic people score below this value, and many non-autistic people score above it. Scores may also be influenced by other conditions or individual differences that overlap with autistic traits.
If you are wondering whether you may be autistic, the CATI may provide a useful starting point for discussion, but only a qualified clinician can determine whether you meet the criteria for an autism diagnosis.
Why are there six subscales?
Autism is complex and cannot be adequately described by a single score alone. People often have different patterns of autistic traits, even when their overall CATI scores are similar.
The CATI therefore measures six broad areas of autistic traits:
- Social Interactions - comfort and confidence in social situations.
- Communication - understanding indirect and non-verbal communication.
- Social Camouflage - masking or compensating for autistic traits in social situations.
- Self-Regulatory Behaviour - repetitive or self-regulating behaviours that may help manage emotions or sensory experiences.
- Cognitive Flexibility - preference for routines and adapting to unexpected changes.
- Sensory Sensitivity - responsiveness to sounds, lights, textures, smells, and other sensory experiences.
Looking at the subscale scores often provides a more meaningful picture than considering the total score alone.
Can the CATI diagnose autism?
No. The CATI was not developed as a diagnostic instrument and should not be used to diagnose autism.
An autism diagnosis involves a comprehensive assessment by appropriately qualified clinicians, who consider developmental history, current functioning, behavioural observations, and information from multiple sources. No questionnaire on its own can provide a diagnosis.
The CATI is best viewed as a way of measuring autistic traits rather than determining whether someone is autistic.
Why did the recommended threshold change?
The recommended threshold has been updated as more evidence has become available.
The original recommendation was based on a relatively small sample of autistic participants collected during the CATI's initial development. Since then, a much larger validation study involving more than 2,600 autistic and non-autistic adults has allowed us to estimate the threshold with much greater precision.
Updating recommendations as new data become available is a normal part of developing and improving psychological questionnaires. It reflects a stronger evidence base rather than a change to the questionnaire itself.
Does the CATI perform similarly across genders?
Current evidence suggests that the CATI performs similarly across gender groups.
The 2025 evaluation demonstrated measurement invariance across cisgender men, cisgender women, and gender-diverse participants. This indicates that the questionnaire measures the same underlying constructs across these groups and that score comparisons are meaningful.
Although average scores may differ between groups, there is currently no evidence supporting the use of different scoring methods or recommended thresholds based on gender.
Why have some terminology and subscale names changed?
Following consultation with autistic advisors during the 2025 psychometric evaluation, some terminology was updated to better reflect contemporary language preferences.
In particular:
- Repetitive Behaviours became Self-Regulatory Behaviour; and
- Cognitive Rigidity became Cognitive Flexibility.
These changes were intended to provide more descriptive and strengths-informed terminology. The underlying constructs measured by the questionnaire have not changed, and the scoring remains equivalent.
How can I contact the CATI team?
We welcome questions, feedback, and suggestions from researchers, clinicians, autistic people, and members of the public.
Please get in touch if you:
- have a question about the CATI or its appropriate use;
- notice an error or technical problem with the website or online questionnaire;
- are planning a translation or cultural adaptation of the CATI;
- have published research using the CATI that you would like us to know about; or
- have suggestions for improving the questionnaire or website.
Email: michael.english@uwa.edu.au
While we are happy to answer questions about the CATI and its use, we are unable to provide individual advice about autism, interpret personal CATI scores, or comment on whether someone may or may not be autistic.
Using the CATI in Research and Clinical Practice
Where can I read about the CATI?
The CATI has been described in two peer-reviewed publications.
The 2021 paper describes the development of the questionnaire, including item generation, factor analysis, reliability, and initial validation.
The 2025 paper presents a large-scale psychometric evaluation involving more than 2,600 autistic and non-autistic adults. It includes updated evidence regarding the CATI's factor structure, reliability, measurement invariance, score interpretation, and recommended threshold for identifying elevated autistic traits.
Both publications are open access and can be downloaded from the Publications section of the home page.
How should I cite the CATI?
If you use the CATI in your research, please cite the original development paper:
English, M. C. W., Gignac, G. E., Visser, T. A. W., Whitehouse, A. J. O., Enns, J. T., & Maybery, M. T. (2021). The Comprehensive Autistic Trait Inventory (CATI): Development and validation of a new measure of autistic traits in the general population. Molecular Autism, 12(1), 37. https://doi.org/10.1186/s13229-021-00445-7
If you discuss the CATI's psychometric properties, recommended threshold, or current normative data, we also recommend citing the 2025 psychometric evaluation.
English, M. C., Poulsen, R. E., Maybery, M. T., McAlpine, D., Sowman, P. F., & Pellicano, E. (2025). Psychometric evaluation of the Comprehensive Autistic Trait Inventory in autistic and non-autistic adults. Autism, 29(12), 2955-2974. https://doi.org/10.1177/13623613251347740
How was the CATI developed?
The CATI was developed to provide a contemporary measure of autistic traits that reflects current understanding of autism.
Development began with a review of diagnostic criteria and emerging research, followed by consultation with researchers, clinicians, and autistic adults. This process generated an initial pool of 107 items covering a broad range of autistic characteristics.
These items were administered to more than 1,200 adults recruited from the general population. Exploratory factor analysis identified six distinct trait domains, from which seven items were selected for each subscale to create the final 42-item questionnaire. A second independent sample of more than 1,100 participants was then used to confirm the factor structure and evaluate the CATI's psychometric properties.
Further evaluation in 2025 substantially expanded the evidence base using a large sample of autistic and non-autistic adults.
Has the CATI been shown to be reliable and valid?
Yes. Evidence from multiple studies supports the CATI as a reliable and valid measure of autistic traits in adults.
Research has demonstrated:
- a stable six-subscale structure that has been replicated across independent samples;
- excellent internal consistency for the total score and strong reliability across all six subscales;
- strong convergent validity with established measures of autistic traits and related constructs;
- measurement invariance across autistic and non-autistic participants, and across gender groups; and
- good discrimination between autistic and non-autistic adults using the total score.
The most comprehensive evaluation to date is reported in the 2025 psychometric study.
Can the CATI be used with autistic participants?
Yes. Although the CATI was originally developed using a general population sample, subsequent research has demonstrated that it performs well in autistic adults.
The 2025 psychometric evaluation included more than 1,300 autistic participants (including both diagnosed and self-identifying autistic adults) and found that the CATI retained strong reliability and the same underlying factor structure observed in non-autistic participants.
These findings support the CATI's use in studies involving autistic participants, non-autistic participants, or comparisons between the two groups.
Can I modify or translate the CATI?
To maintain the CATI's published psychometric properties, modifications to the questionnaire are discouraged. This includes changing item wording, altering the response scale, removing items, or changing scoring procedures.
Researchers wishing to administer the CATI electronically or incorporate it into survey software should ensure that the wording, response options, and scoring remain identical to the published version.
If you wish to translate the CATI into another language or adapt it for a specific population, please contact us before beginning the translation process. We are keen to support high-quality translations while maintaining consistency across versions.
Can I use the CATI in clinical practice?
The CATI was developed primarily as a research instrument and has not been validated as a stand-alone diagnostic assessment.
However, clinicians may find the CATI useful as a structured measure of autistic traits to complement other sources of clinical information. The total and subscale scores can help identify areas that may warrant further discussion during assessment.
The CATI should always be interpreted alongside developmental history, clinical interview, behavioural observations, and other validated assessment tools. It should not be used in isolation to diagnose or exclude autism.