Executive function and time

Executive functions are the mental processes used to hold a goal in mind and steer toward it. A widely cited review names three core ones: inhibition (holding back a habitual response or ignoring distraction), working memory, and cognitive flexibility.¹ In one study of 137 college students, these three were related to each other but could be told apart.²

Pooling 235 studies with 6,816 autistic people, autistic groups scored lower than non-autistic groups on executive tasks by a moderate amount (g = 0.48). The size of the gap was similar in every domain and fairly stable across ages, and no domain differed more than the others.³ Only a few tasks separated autistic from non-autistic people well enough to help with diagnosis, and in this meta-analysis the gap was smaller in more recent studies.³

Meta-analyses of single domains find gaps of a similar size. In children and adolescents without intellectual disability, differences ran from g = 0.41 for inhibition to 0.67 for verbal working memory, and differences in flexibility, generating ideas and working memory remained when autistic participants had no ADHD or were matched on IQ.⁴ For planning, the difference across 50 studies was 0.52, or 0.37 after allowing for unpublished negative results.⁵ For inhibition, it was 0.55 for holding back a habitual response and 0.31 for ignoring distraction.⁶ For flexibility, 59 studies of autistic people aged 4 to 85 found a small-to-moderate difference, largest for perseverative errors.^7,8

Each of these meta-analyses also reports wide variation between studies.^6,7 Averages describe groups, not individuals. In one study of 110 autistic adults and 31 comparison adults, the autistic group was more likely to score in the clinically impaired range, yet 35.8% of them showed no impairment on any executive measure.⁹

Across 83 studies, groups with ADHD scored lower on every executive task, with medium effect sizes from 0.46 to 0.69. The largest and most consistent differences were in response inhibition, sustained attention (vigilance), working memory and planning, and they were not explained by IQ, school achievement or other conditions.¹⁰ The differences were not found in everyone with ADHD, and the authors concluded that executive weaknesses are "neither necessary nor sufficient" to account for all cases.¹⁰

A review of 34 meta-analyses found an average difference of about 0.45. Working memory (0.54), response inhibition (0.52) and planning (0.51) were near the top and set shifting (0.35) was lowest.¹¹ Differences in areas not usually counted as executive were comparable: 0.53 for how much reaction times varied and 0.51 for intelligence and school achievement (0.66 and 0.60 when weighted by the number of studies), so the profile is broad rather than specifically executive.¹¹ Differences were smaller in adolescents than in children or adults, and meta-analyses with drug-company funding reported larger effects.¹¹

In adults with ADHD, a 2005 meta-analysis of 13 studies found medium differences on executive tasks and also on tasks that are not executive, such as how consistent responses were and how fast colors and words were named.¹²

Executive function is measured in two ways: timed tasks in a lab, and questionnaires about everyday behavior filled in by a parent, a teacher or the person themselves. Across 20 studies, only 68 of 286 correlations between the two (24%) were significant, and the typical correlation was .19. The reviewers concluded that the two measure different things: tasks capture how efficiently a skill works under controlled conditions, ratings capture how well a person gets things done in daily life.¹³ In a meta-analysis of 180 child studies, executive differences were larger when measured with ratings than with tasks.¹⁴

The most used questionnaire is the BRIEF. In 185 autistic children and teenagers without intellectual disability, scores for starting tasks, working memory and organizing materials were further from the norms in older age groups. Flexibility was the most elevated scale in both the youngest and the oldest.¹⁵ The study compared different children at different ages and did not follow the same children over time.

In 110 autistic adults, everyday executive difficulties were common and were not related to how the same adults did on executive tasks.⁹ In 197 autistic teenagers, both the teenagers and their parents reported executive problems and both rated flexibility as the hardest area, but they disagreed on how severe the problems were. The autistic teenagers' self-reported profile differed from that of 114 teenagers with ADHD, also without intellectual disability.¹⁶

On executive tasks, autistic and ADHD children look much alike. A meta-analysis of 58 direct comparisons found no differences between the two groups; both differed from typically developing children on attention, flexibility, working memory, processing speed and inhibition, and neither differed on planning.³⁵ A second meta-analysis, of 36 studies, also found no difference on tests (d = 0.02), but on questionnaires ADHD groups were rated as having more difficulty (d = -0.34). Children with both conditions had a profile closer to ADHD alone and more difficulty than autistic children without ADHD.³⁶

An earlier narrative review of 26 studies had suggested that children with both share flexibility and planning difficulties with autistic children and inhibition difficulties with children with ADHD, the two adding together.¹⁷ The later meta-analyses, which found little difference between autism and ADHD, do not support a clear split of that kind.

In 317 children aged 8 to 13 (30 autistic without ADHD, 93 with ADHD, 66 with both, 128 typically developing), groups formed from executive scores did not match diagnostic groups. The lowest-scoring group was mixed, but children with both conditions made up the largest share of it (45%), and 92% of children with both fell into it, against 47% of the 30 autistic children without ADHD.¹⁸ In 100 autistic teenagers from a population sample, executive task scores tracked ADHD traits rather than autistic traits.¹⁹

Across 180 child studies, executive differences were larger in children with more than one condition (g = 0.72) than across all conditions (g = 0.56).¹⁴ In a small Swedish clinic sample, youths with any two neurodevelopmental conditions (not necessarily autism and ADHD) had more parent-rated problems in four of nine BRIEF-2 areas than youths with one, the largest for flexibility.²⁰

Autistic people have long described difficulty acting on their own intentions, often called autistic inertia. The first study of it, led by an autistic researcher, held focus groups with 32 autistic adults aged 23 to 64.²¹ Participants described difficulty starting, stopping and changing activities that was not under their conscious control. Difficulty with planning was common. A subset described being unable to start even simple actions, which the authors suggested was closer to a movement disorder.²¹

Participants reported that prompting from someone else, and related activity going on around them, made it easier to act, and that stress and poor mental health made it harder.²¹

Across 55 studies, people with ADHD were less accurate than others at telling apart very short durations, especially under a second, and more variable when judging durations of several seconds. Their estimates and productions of intervals were less accurate, a pattern the authors read as a sign of an internal clock that runs fast.²² In a meta-analysis of 27 studies of children and adolescents, timing was less accurate (g above 0.40) and less precise (g = 0.66), with a tendency to overestimate how much time had passed. The type of task and the kind of stimulus did not change the result.²³

A related difference concerns the value of waiting. Across 25 comparisons with 3,913 participants, people with ADHD discounted delayed money more steeply than others, preferring a smaller reward sooner (d = 0.43), and the size of the difference did not differ between samples under and over 18.²⁴

One influential model holds that ADHD centers on weaker behavioral inhibition, which in turn affects working memory, self-regulation and other executive functions. Its author wrote that far more research was needed to test it.²⁵ A later study of 71 children and teenagers with ADHD found that difficulties with timing, inhibition and waiting for rewards were separate: in individual children they occurred together no more often than chance, and many children had only one of them. Its authors asked for larger studies to check this.³⁷

A systematic review of 45 papers found no consensus on whether timing works differently in autism. Differences were most consistent in tasks about higher-level time perception and less consistent in simple timing tasks.²⁶ For one narrow skill, judging which of two brief events came first or whether they were simultaneous, a meta-analysis found a moderate difference overall (g = 0.48): moderate for speech sounds and small for other stimuli.²⁷

Small studies point in several directions. In 17 autistic children compared with 18 others matched on age and IQ, telling apart durations under a second was harder but telling apart longer ones was not, and estimates of intervals lasting minutes did not differ. Parents rated the autistic children's sense and management of time lower.²⁸ In 18 autistic people judging intervals of about a second, timing followed the same basic rule as in other people but was less sensitive to small differences.²⁹ In 118 children with various disabilities, including ADHD and autism, a test of understanding time went with parents' ratings of how well the child managed time day to day.³⁰

Body doubling began as a community practice, used mainly by neurodivergent people. In a survey of 220 people, it was described as using the presence of others to start, stay focused on, or finish a task. The other person can be in the room or remote, live or recorded, a friend or a stranger, and the tasks ranged from study and work to dishes and exercise.³² Most participants had used it long before they learned the name.^31,32 The 2023 paper on this survey stated that no academic research on the topic existed.³¹

The only experiment found is a preprint: 12 young adults who screened positive for ADHD did a virtual-reality building task faster with a human or an AI body double than alone, though their accuracy did not differ.³³ Searches of PubMed and CrossRef (October 2026) found no randomized trial, no study of autistic people specifically, and no study comparing people with autism, ADHD or both.

In community writing, "executive dysfunction" names everyday trouble getting from an intention to an action. Megan Griffith describes it from the inside: "When you experience executive dysfunction, you often feel like you're not the one in charge of your brain."^c1 She sees it as mainly an ADHD struggle that autism complicates, through what she calls "step thinking": a sense that tasks must be done in one correct order, which makes getting out of the door harder.^c2 Sarah Nannery, an autistic writer, warns against reading it as mess. She counts herself among people who are "extremely organized" and still have executive difficulties, which she says "will differ greatly from person to person."^c7

Autistic inertia is the community's name for difficulty starting, stopping and switching. Megan Anna Neff calls it a "stop-and-go struggle" and suggests small steps, alarms and visual cues, tying a task to a special interest, and a five-minute timer.^c4 Devon Price links it to the same focus that holds a special interest for hours, and writes that onlookers read it as laziness: "Almost every neurodiverse person I've spoken to has been deemed 'lazy' numerous times by exasperated parents, teachers, and friends."^c5

Maxfield Sparrow writes of "something that we Autistics have come to call 'Autistic inertia'", and recalls researching a paper for twenty hours straight, unable to switch to writing even with enough material in hand.^c8 Pete Wharmby stresses that inertia is "independent of any desire to do the other activity", unlike procrastination, so it can block things a person would enjoy.^c9 Mel Baggs, who had help with every part of daily living, wrote that skills learned in training did not carry over to living alone: "It's one thing to know in theory how skills work."^c11 Daniel Burford suggests plans decided once in advance, in the form "when X happens, I do Y", so that "the situation does the starting instead of you."^c12

On time, Griffith writes that AuDHDers are often late "because we couldn't accurately perceive the passage of time, or because we got caught up in a million side quests".^c2 Price draws on the writer Marta Rose, who calls schedules built on the factory workday "Industrial Time" and suggests thinking of time as a spiral of cycles rather than a straight line.^c5 Wharmby describes "future-blindness", being unable to picture anything much more than a month ahead, and asks, "After all, how can you plan for a future that you literally cannot conceptualise?"^c13 Wharmby wonders whether this, as much as procrastination, is why many autistic and ADHD people do most of their work just before a deadline.^c13

Body doubling is described mostly by ADHD and AuDHD writers. Griffith works alongside friends, family, recorded videos and online coworking groups, and finds it "hugely effective for nearly all ADHDers and most AuDHDers, but it may be less effective for autistic folks", because company can set off the urge to mask.^c3 Price describes a friend's weekly "productivity circles" and reports that neurodivergent writers including Ayesha Khan, Jesse Meadows and Marta Rose have criticized the idea of executive dysfunction itself, arguing that people have always needed company to get hard or boring tasks done.^c6 Price also writes that research on social facilitation shows almost everyone performs better when work is shared.^c6 The research above finds no general boost from the presence of others, at least for physical tasks.

Kaegan Smith, who began communicating by spelling on a letterboard at 18, describes a gap between what the mind intends and what the body does: "My life was spent knowing that my body would act in opposition to my brain."^c10