Time blindness

Even intervals from under a second to a few seconds can be misjudged

Research-backed

Time difficulties in attention-deficit/hyperactivity disorder (ADHD) are not limited to planning schedules. In experiments judging intervals from under a second to a few seconds, ADHD groups were also less accurate than controls(Marx et al., 2022).

Three meta-analyses agree(Marx et al., 2022; Zheng et al., 2020; Metcalfe et al., 2024). One reported an average group difference of g = 0.688: comparing one randomly chosen person from each group, the person with ADHD would time worse about 69% of the time(Metcalfe et al., 2024) (an approximate conversion).

The remembered “last time” that estimates rely on is already too short

Research-backed

When estimating how long a task will take, people tend to draw on how long similar tasks took in memory. Remembered durations are usually shorter than the actual time, so estimates based on them come out short as well(Roy et al., 2005). People also often estimate from an imagined plan rather than checking past experience(Buehler et al., 1994).

This bias is not unique to ADHD. However, a small study found that after completing a task resembling schoolwork, college students with ADHD misremembered how long it took by more than controls(Prevatt et al., 2010).

Estimates swing long and short; accurate once is not accurate next time

Research-backed

In experiments, estimates of intervals lasting a few seconds tend to vary more in people with ADHD, rather than simply being consistently too short or too long(Marx et al., 2022; Zheng et al., 2020). In a child meta-analysis, the group difference in this variability was g = 0.66: people with ADHD varied more about 68% of the time (an approximate conversion)(Zheng et al., 2020).

Time difficulties can occur alone, without impulse control difficulties

Proposed in research

Several studies divided ADHD difficulties into categories such as timing, impulse control, and responses to rewards and waiting; many people had a deficit in only one category(Sonuga-Barke et al., 2010; de et al., 2012). In one study, 80% of ADHD participants with a cognitive deficit had it in only one category(de et al., 2012). In another, about 31% of boys with ADHD had a timing deficit(Coghill et al., 2013).

A review also concluded that timing deficits seem to remain after accounting for attention and working memory(Noreika et al., 2013). So people with normal impulse control may still have clear time difficulties, and not everyone with ADHD has a timing deficit.