Why intelligence scores do not predict success for autistic adults

The idea that a high level of intelligence helps some autistic people in their daily lives crops up often in Hollywood depictions and casual conversation. The concept even has some scientific support. In the late 1960s and early 1970s, several researchers suggested that a high intelligence quotient (IQ) helps autistic people better engage in their communities, social interactions and education^1,2,3.

In part because of this early work, IQ remains one of the most common ways to evaluate abilities among autistic people.

Yet we now know that it is not really possible to match IQ to a designated level of function. Relying on IQ and using labels such as ‘high functioning’ and ‘low functioning’ minimizes the daily difficulties encountered by all autistic individuals. It also can obscure considerable unmet needs. Or, as the autistic writer and advocate Laura Tisoncik eloquently put it: “The difference between high functioning and low functioning is that high functioning means your deficits are ignored, and low functioning means your assets are ignored.”

A better predictor for independence is the ability to meet daily demands, from managing a home to keeping a schedule and brushing one’s teeth — also called adaptive functioning. This is particularly true for autistic people who do not have intellectual disability. By failing to use adaptive functioning measures to assess everyday difficulties and identify support needs, we’re doing a disservice to a broad swath of the autism community.

In the most recent edition of psychiatry’s official guide, the “Diagnostic and Statistical Manual of Mental Disorders” (DSM-5), there has been a shift away from IQ scores to measure the degree of intellectual disability. Instead, the DSM-5 uses age-standardized adaptive functioning scores to gauge functional needs. These scores encompass communication, interpersonal skills, social responsibility, personal care and safety — skills that enable independence in the face of changing environmental demands.

Hidden struggle:

The trouble is, the DSM-5 only indicates using these assessments for autistic people who have intellectual disability. This leaves out those autistic people without intellectual disability who may benefit the most from using adaptive functioning as a measure of everyday skills and difficulties as well as potentially unmet needs. In these individuals, cognitive skill, as measured by their IQ score, is likely to mask the extent to which they struggle to meet everyday demands⁴.

This is true not only for adults, but also for children and adolescents, whose adaptive functioning gains may not keep pace with those of their neurotypical peers⁵. The gap between IQ and adaptive functioning may also be linked to mental-health risks, such as depression and anxiety, further supporting the idea that an average IQ doesn’t protect against all factors that can erode quality of life⁶.

The cause of this mental-health risk is unclear. Although it is conceivable that high IQ leads to greater anxiety and depression among autistic adults, other factors probably contribute as well. For example, any adult may feel pressure to meet certain social expectations, including earning a college degree, obtaining a job, getting married, having close friendships and living independently. The perceived failure to meet these expectations could harm anyone’s mental health, and autistic adults are particularly vulnerable.

Autobiographical accounts by adolescents and adults diagnosed with autism later in life reveal the consequences to mental health of many years of unmet adaptive needs. These individuals often feel they have failed on many fronts, because they lacked a support network to succeed⁷. If a person’s needs aren’t recognized, it’s difficult for her to realize that her perceived shortcomings are not her fault.

Quality of life:

The research on adaptive functioning in autistic adults without intellectual disability is lacking in scope and depth. Perplexingly, studies of treatments rarely focus on adaptive skills for autistic people in adolescence and adulthood, though efforts conducted over the past year are beginning to rectify this⁸.

In addition, there is a critical need for a distinction between a lack of adaptive skills, the absence of appropriate supports such as accommodations and formal services, and general unmet needs. As a result, we can’t tease out whether poor outcomes are due to impairments, a lack of support, a combination of the two or something else entirely.

Poor adaptive skills without adequate supports may explain the dismal higher-education and employment rates among autistic adults. This is particularly true for those without intellectual disabilities, who may be presumed capable of attending college or pursuing competitive employment without a need for significant supports. In fact, however, these individuals often have significant impairments in basic day-to-day functions.

Autistic adults who struggle the most with adaptive functioning may also be more likely to be placed under the care of a guardian or in a group home. And they may be more likely to depend on others for transportation and access to the community.

Identifying these potential problems is critical for making positive changes in the lives of autistic adults. The primary goal of any service for autistic people should be to improve their quality of life. Focusing on adaptive functioning enables us to provide the support autistic people need to meet their goals for independence, self-determination, education, employment and social engagement.

It is important to recognize that better assessment and a greater focus on skill-building will not eliminate adaptive functioning difficulties among autistic adults. Autism is a lifelong developmental disability, and most autistic adults need regular support in one form or another for the rest of their lives. And that’s okay.

From research on individuals with intellectual disability, we know that even among those who need significant day-to-day support, a high quality of life and positive outcomes, such as life satisfaction, happiness and successful employment, are still possible^9,10. There is no reason to think autistic people are any different.

Gregory Wallace is assistant professor of speech, language and hearing sciences at George Washington University in Washington, D.C. Julia Bascom is executive director of the Autistic Self Advocacy Network in Washington, D.C.