People high in neuroticism report sleeping less, but wrist monitors tell a different story

Young adults who scored higher in neuroticism reported sleeping less, but a wrist-worn sleep monitor did not show that they actually slept less, according to a study published in Personality and Individual Differences.

Neuroticism is a personality trait associated with a greater tendency to experience negative emotions, such as worry and distress. Previous research has found that people with higher neuroticism often report shorter sleep. But studies using actigraphy, which relies on a wearable device to estimate sleep from movement, have generally not found the same relationship.

To examine this discrepancy, Derick M. DeCamp and Elizabeth J. Pantesco of Villanova University looked at both kinds of sleep measures in the same group of people. The study included 134 undergraduate students (average age 19; 95 women) without diagnosed sleep disorders.

Participants wore a wrist actigraph for five nights, including two weekend nights, and completed questionnaires about their personality, sleep, and symptoms of depression and anxiety. The researchers measured reported sleep over the past month in two ways: participants directly estimated how many hours of actual sleep they usually got, and the team calculated sleep duration from participants’ usual bedtime, wake time, and time taken to fall asleep.

Higher neuroticism was linked to shorter sleep on both self-report measures, but not to sleep duration as estimated by the actigraph. The differences were modest: each one-point increase in neuroticism on a five-point scale was associated with roughly 15 to 20 fewer minutes of reported sleep. The connection between neuroticism and self-reported sleep remained after the researchers accounted for actigraphy-estimated sleep, demographic characteristics, body mass index, depression and anxiety symptoms, night-to-night sleep regularity, and other personality traits.

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The study’s average sleep estimates illustrate how measurement methods can differ. Participants reported 6.74 hours of sleep on the direct question, while the actigraph estimated 6.70 hours, and the calculated self-report estimate was higher, at 7.40 hours. Compared with the actigraph, participants higher in neuroticism tended to underestimate their sleep on the direct question and to overestimate it less on the calculated measure.

Symptoms of depression and anxiety were closely related to neuroticism but were not themselves linked to how long participants slept or reported sleeping, and accounting for them did not weaken the association. The authors suggest this points to a role for the stable personality trait rather than temporary distress.

The authors wrote that their findings are “consistent with the possibility that neuroticism is more strongly related to how individuals perceive, recall, and report their sleep duration than to actigraphy-assessed sleep duration.” They suggested that people higher in neuroticism might recall or interpret their sleep more negatively, or that worry before bed might make it feel as though falling asleep takes longer. These explanations remain speculative, as the researchers did not directly measure recall errors or reporting bias.

The authors also noted other possibilities. People higher in neuroticism might spend more time lying still but awake in bed, which an actigraph can mistake for sleep, and because both neuroticism and habitual sleep were self-reported, part of the association may reflect shared reporting tendencies.

Some limitations should be noted. The questionnaires asked about sleep during the previous month, while the actigraph recorded only five nights, which may not be enough to reliably capture typical sleep; the mismatch also makes direct comparisons harder. Participants may also have altered their sleep because they knew it was being monitored, and the sample consisted of college students, most of them women, from a single private university.

The study, “Neuroticism is associated with self-reported, but not actigraphy-assessed, sleep duration,” was authored by Derick M. DeCamp and Elizabeth J. Pantesco.