Level 1 autism and “high-functioning autism” refer to overlapping groups of people, but they are not interchangeable terms, and the label “high-functioning” is increasingly rejected by clinicians and autistic people alike. Level 1 is the current diagnostic designation in the DSM-5, describing individuals who need “support” (as opposed to Level 2’s “substantial support” or Level 3’s “very substantial support”). “High-functioning autism” was never an official diagnosis; it grew informally as a shorthand for autistic people without intellectual disability. The trouble is that the phrase sets up expectations that do not match reality for many people living with Level 1 autism.
How the Two Labels Relate
Before 2013, the diagnostic landscape looked different. Asperger syndrome, autistic disorder, and pervasive developmental disorder-not otherwise specified were separate diagnoses. “High-functioning autism” was used casually to describe people with autism who had average or above-average IQ scores, distinguishing them from individuals with co-occurring intellectual disability. When the DSM-5 collapsed these categories into a single autism spectrum disorder with three severity levels, “high-functioning” lost whatever loose diagnostic footing it had. The people formerly labeled with Asperger syndrome or “high-functioning autism” generally fall into Level 1 under the new system, though the mapping is imperfect. Research comparing children previously diagnosed with Asperger syndrome and those labeled high-functioning autism found genuine differences in cognitive profiles, language development, and school functioning, suggesting even the old informal categories were not as tidy as they appeared.1SpringerLink. Subtyping the Autism Spectrum Disorder: Comparison of Children with High Functioning Autism and Asperger Syndrome
Level 1, as defined by the DSM-5, focuses on how much support a person needs rather than how “well” they appear to function on the surface. That is a meaningful distinction. A person who holds down a job and makes eye contact in conversation might still need significant support with planning meals, managing appointments, or recovering from social interaction. The level system was designed to capture that, though as we will see, even the level ratings have their own reliability problems.
The Gap Between Intelligence and Daily Life Skills
The core problem with calling anyone “high-functioning” based on their IQ is that intelligence is a poor predictor of how well someone manages day-to-day life. A large body of research now shows that autistic people without intellectual disability consistently score lower on measures of adaptive functioning, things like self-care, communication in real-world settings, household tasks, and navigating social situations, than their IQ scores would predict. One study described this as “an imprecise proxy for functional abilities,” concluding that the term “high functioning autism” should be abandoned in both clinical and research settings because IQ-based labels mislead everyone involved.2PubMed. The misnomer of ‘high functioning autism’: Intelligence is an imprecise predictor of functional abilities at diagnosis
This gap between IQ and adaptive skills is not just present; it gets wider over time. Research tracking autistic individuals found that the discrepancy between measured intelligence and real-world adaptive functioning grew with age, particularly in communication and daily living skills.3PubMed Central. The Gap between IQ and Adaptive Functioning in Autism Spectrum Disorder: Disentangling Diagnostic and Sex Differences Additional work confirmed that cognitive-adaptive functioning gaps increased as IQ went up, meaning the smarter a person appeared on paper, the more surprising and severe the mismatch with their practical abilities could be.4Neuropsychiatric Disease and Treatment. Effects of Intelligence Levels and Autistic Severity on Adaptive Functioning and Cognitive-Adaptive Functioning Gaps in School-Aged Children with Autism Spectrum Disorder For anyone who has watched a Level 1 autistic adult ace a technical exam and then struggle to cook a basic meal or return a phone call, this pattern will feel familiar.
Why Level 1 Autism Looks “High-Functioning” From the Outside
A major reason Level 1 autism gets equated with high functioning is that many autistic people actively work to appear non-autistic. This process, known as camouflaging or masking, involves consciously suppressing autistic behaviors like stimming, rehearsing scripts for small talk, forcing eye contact, and mimicking the social rhythms of people around them. A qualitative study of 92 autistic adults developed a three-stage model of how this works: people are motivated to fit in and build connections, they use a combination of masking and compensation techniques to do so, and then they deal with consequences including exhaustion and threats to their sense of self.5PubMed Central. “Putting on My Best Normal”: Social Camouflaging in Adults with Autism Spectrum Conditions
The cost of all this performance is steep. Research into autistic adults’ experiences of camouflaging found that the cumulative time spent masking led to exhaustion, isolation, poor mental and physical health, loss of identity, and delayed diagnosis. Participants described others forming unrealistic expectations of what they could handle, precisely because the mask was so effective.6PubMed Central. Autistic Adults’ Experiences of Camouflaging and Its Perceived Impact on Mental Health In other words, the very behavior that makes someone look “high-functioning” to an outside observer is also what puts their wellbeing at risk. The label rewards the performance and ignores the toll.
Executive Functioning and the Hidden Struggle
Even when cognitive ability is intact or strong, executive functioning often is not. Executive functions are the mental processes that let you plan, initiate tasks, shift between activities, hold things in working memory, and monitor your own progress. These are the gears behind getting out of the house on time, managing a household budget, or switching focus when a meeting topic changes. Adults with autism show deficits across all measured executive function domains compared to population norms, with the most pronounced difficulties in cognitive flexibility (shifting between tasks or ideas), initiating activities, working memory, and planning.7PubMed Central. Real-World Executive Functions in Adults with Autism Spectrum Disorder: Profiles of Impairment and Associations with Adaptive Functioning and Co-morbid Anxiety and Depression
These are not abstract deficits. Executive functioning difficulties predict lower adaptive behavior and poorer mental health in autistic children and adults alike.8PubMed. Everyday executive function predicts adaptive and internalizing behavior among children with and without autism spectrum disorder They also predict employment outcomes: autistic young people with executive functioning challenges are less likely to find and keep jobs.9PubMed Central. Early Employment Outcomes in Autistic and Non-autistic Youth: Challenges and Opportunities Someone who is articulate and knowledgeable can still find it genuinely difficult to organize laundry, start a work assignment without external pressure, or recover from an unexpected schedule change. None of this is visible in an IQ score.
Mental Health and Burnout
The assumption that Level 1 means “mild” problems leads to another dangerous blind spot: mental health. Among adults who received an autism diagnosis in adulthood, roughly 37% reported moderate to severe anxiety and 46% reported moderate to severe depression.10Research in Autism Spectrum Disorders. Exploring the anxiety and depression profile in individuals diagnosed with an autism spectrum disorder in adulthood These are people who, by definition, went years or decades without their autism being identified, often because they appeared to be managing. Many received a string of other mental health diagnoses first: anxiety disorder, depression, personality disorders, eating disorders. The autism was the last piece of the puzzle, not the first.
Masking itself feeds this cycle. Research specifically linking masking behaviors to mental health outcomes has found that increased camouflaging is associated with increased depression, anxiety, burnout, and exhaustion.11PubMed Central. What You Are Hiding Could Be Hurting You: Autistic Masking in Relation to Mental Health, Interpersonal Trauma, Authenticity, and Self-Esteem When masking finally becomes unsustainable, the result is often what is now called autistic burnout: a state of chronic exhaustion, sensory overload, and executive dysfunction that disrupts daily life. Recent research describes people engaging in “dual-masking,” hiding both their autistic traits and the signs of burnout itself, which delays recognition and makes recovery harder.12PubMed Central. Beyond Exhaustion: Shame, Identity Disruption, and Functional Collapse in Autistic Burnout
Suicidality rates paint an especially stark picture. A meta-analysis of over 48,000 autistic people without intellectual disability found that about a third reported suicidal ideation, roughly one in five had made a suicide plan, and about one in four had attempted suicide or engaged in suicidal behavior.13PubMed Central. A systematic review and meta-analysis of suicidality in autistic and possibly autistic people without co-occurring intellectual disability These numbers apply precisely to the population most often called “high-functioning.” Separate research found that the combination of autism and high cognitive ability was actually associated with a striking increase in suicidal ideation, with one clinical sample showing roughly six times the odds of parent-reported suicidal thoughts among autistic youth with IQs of 120 or above.14PubMed Central. The combination of autism and exceptional cognitive ability is associated with suicidal ideation That finding runs exactly counter to the “high-functioning means fewer problems” assumption.
Sensory Processing Is Often Invisible
Sensory differences are a core feature of autism, but they are easy to overlook in someone who seems socially capable. Level 1 autistic people commonly experience both hyper-reactivity (being overwhelmed by sounds, lights, textures, or smells that others barely notice) and hypo-reactivity (not registering certain stimuli, like pain or temperature changes). A qualitative study identified seven distinct aspects of sensory experience in autistic adults without intellectual disability, including reactions to general overload, strong stimuli preferences, and the challenge of managing the downstream consequences of sensory reactions in daily life.15PubMed. Too much or too little: hyper- and hypo-reactivity in high-functioning autism spectrum conditions
These sensory differences are not minor annoyances. Research focused specifically on Level 1 autism has found that sensory amplification and autonomic dysregulation are central to the experience of overwhelm, directly shaping cognition, emotional regulation, and how much a person can actually get done.16Journal of Educational & Psychological Research. The Body That Thinks: Sensory Processing, Autonomic Dysregulation, and the Embodied Experience of Level 1 Autism Spectrum Disorder A fluorescent-lit open-plan office, for example, can be functionally disabling for someone whose nervous system processes that lighting as painfully intense, regardless of how “well” they scored on a cognitive test. There is also growing evidence of a link between autism and autonomic dysfunction: a study of autistic adults found that the large majority had a diagnosable autonomic condition, with postural tachycardia syndrome being particularly common.17PubMed Central. Autonomic Dysfunction in Autism Spectrum Disorder These physical experiences shape daily functioning but are rarely captured in a label like “high-functioning.”
Employment Tells a Different Story Than the Label Suggests
If Level 1 autism really meant easy sailing, you would expect employment outcomes to be close to the general population. They are not. Autistic young people are less likely to obtain jobs through competitive hiring and tend to end up concentrated in sales and retail roles rather than career-track positions, while their non-autistic peers show greater job diversity.9PubMed Central. Early Employment Outcomes in Autistic and Non-autistic Youth: Challenges and Opportunities International research identifies stigma, a lack of employer understanding of autism, and communication differences as key barriers, with autistic individuals reporting significant difficulty both getting and keeping jobs.18PubMed. Multi-informant International Perspectives on the Facilitators and Barriers to Employment for Autistic Adults
The workplace is also where the friction between competence and support needs becomes most visible. An autistic person might perform their core job duties brilliantly but struggle with unwritten social rules in the break room, the sensory assault of a shared workspace, or the executive-functioning demands of managing emails, deadlines, and interruptions simultaneously. When they are labeled “high-functioning,” the struggles are dismissed as personal failings rather than recognized as disability-related needs.
Gender, Diagnosis, and Who Gets Missed
The “high-functioning” framing has had especially harsh consequences for autistic women and girls. The female autism phenotype theory suggests that autistic women often present with less obvious social impairments than autistic men, partly because girls are socialized from a young age to attend to social cues and relationships. One study found that autistic women had typically received more mental health diagnoses before their autism was identified than autistic men had, reflecting years of misdiagnosis.19PubMed Central. Shining a Light on a Hidden Population: Social Functioning and Mental Health in Women Reporting Autistic Traits But Lacking Diagnosis
In-depth interviews with women diagnosed in late adolescence or adulthood reveal a pattern of “pretending to be normal,” with multiple participants describing how their gender led professionals to overlook their autism. These women also reported specific vulnerabilities linked to being female with undiagnosed autism, including widespread experiences of sexual abuse in one study sample.20PubMed Central. The Experiences of Late-diagnosed Women with Autism Spectrum Conditions: An Investigation of the Female Autism Phenotype A narrative review of the evidence concluded that autism may be underdiagnosed in females in part because women and girls express their autism in ways that do not neatly match current diagnostic criteria, with camouflaging playing a central role in the diagnostic gap.21Review Journal of Autism and Developmental Disorders. The Female Autism Phenotype and Camouflaging: a Narrative Review The better someone is at masking, the more “high-functioning” they appear, and the less likely they are to receive accurate support.
The Double Empathy Problem and Social Friction
A common assumption is that autistic people lack social skills in some absolute sense. Research on what is called the “double empathy problem” challenges this. A study had non-autistic observers watch conversations between pairs of people: both autistic, both non-autistic, or one of each. Observers rated the mixed autistic/non-autistic interactions as the least successful, but they rated autistic-autistic interactions more favorably. Conversation partners who actually interacted with autistic people rated them more positively than outside observers did.22PubMed Central. Non-autistic observers both detect and demonstrate the double empathy problem when evaluating interactions between autistic and non-autistic adults The difficulty, in other words, is not that autistic people cannot socialize. It is that the gap between autistic and non-autistic communication styles creates friction in cross-neurotype interaction. Labeling one side of that gap “high-functioning” frames the autistic person’s communication as the deficient one rather than acknowledging a two-way mismatch.
Problems With the Level System Itself
If “high-functioning” is misleading, is Level 1 much better? The level system at least focuses on support needs rather than surface appearance, but its reliability has real limits. A recent study had four doctoral-level clinicians independently evaluate the same group of toddlers and then compared how consistently they assigned DSM-5 severity levels. Agreement on the social communication domain was only fair, and agreement on restricted and repetitive behaviors was slight, even though the same clinicians had shown high agreement on whether the children met criteria for autism at all.23PubMed. DSM-5-TR Severity Levels for Autism Spectrum Disorder (ASD): Agreement Between Clinicians Using Telehealth and In-Person Assessment Procedures The researchers concluded that assigning an autism diagnosis and determining what level of support someone needs are distinct clinical decisions, and the second one is considerably harder to get right. A person’s level can also change over time, depending on life circumstances, burnout, or the availability of support structures. The system is better than the old one, but it still flattens a complex, shifting set of needs into a single number.
Aging With Level 1 Autism
Most autism research and public attention focuses on children and young adults. What happens as Level 1 autistic people age is an area where the evidence is thin but concerning. A study comparing cognitive patterns across age groups found that while both autistic and non-autistic adults showed age-related cognitive decline, autistic adults showed disproportionately larger age effects on executive functioning tasks.24PubMed. Patterns of Age-Related Cognitive Differences in Adults with Autism Spectrum Disorder Since executive functioning is already a weakness for many autistic people, accelerated decline in this area could compound existing difficulties with planning, organization, and adapting to change. The adaptive functioning gap that widens with age in younger autistic people may steepen further in midlife and beyond. This is a population that often lacks the formal support systems available to people with intellectual disabilities, because the “high-functioning” label led everyone to assume they would be fine on their own.