Chronic sleep restriction affects the association between implicit bias and explicit social decision making☆
Introduction
Chronic sleep restriction (eg, restricting sleep on weekdays and catching up on the weekends) is prevalent in modern society. Although the National Sleep Foundation recommends 7-9 hours of sleep per night,9 around 44% of Americans get less than 7 hours of sleep on weekdays and try to catch up on sleep on weekend nights.5 In a recent study, we demonstrated that chronic sleep restriction influences negative implicit biases toward a particular minority group using the Arab Muslim version of the Implicit Association Test (IAT).1 The IAT is a commonly used test that measures the strength of automatic associations between a concept (eg, a minority group) and an evaluation (eg, good and bad). Specifically, our prior results indicated that whereas individuals showed no evidence of a negative implicit bias toward Arab Muslims when fully rested (ie, given the opportunity to sleep for 8 hours per night for 3 weeks), evidence of negative implicit biases emerged within these same individuals when sleep was restricted to 4 hours per night on weekdays (and 8 hours on weekends) for 3 consecutive weeks.1 Thus, our previous work suggested that chronic insufficient sleep can adversely affect social perceptions of minorities, whereas regular nightly sleep appeared to minimize or prevent such biases.
Studies have shown that negative implicit biases toward minority groups, as measured using the IAT,8 might also influence explicit discriminatory behavior. For example, one study showed that individuals with higher implicit bias scores on the Arab Muslim Names IAT were less likely to invite someone with an Arab Muslim name vs a Swedish name to a job interview despite identical resumes of the candidates.15 However, it is currently unknown whether increases in implicit bias as a result of sleep restriction also influence explicit judgments and behaviors. Despite this current lack of knowledge, there is some evidence to suggest that total sleep deprivation impacts some aspects of social perception, such as the perception of facial expressions. This alteration in emotional facial perception may lead to differences in judgments about an individual's level of trustworthiness, but it is worth noting that the nature of the findings remains mixed. For example, whereas some research has shown that neutral facial expressions were most adversely affected by sleep loss,13 other studies find that the recognition of some specific emotions may be impaired, such as anger,11, 20 happiness,11 or sadness.3 Furthermore, another study has shown that the ability to identify the dominant emotion from facial expressions displaying complex emotional blends (eg, fear and surprise) was significantly reduced after sleep deprivation, indicative of a more global emotion recognition deficit.10 Finally, one study investigated specifically whether sleep deprivation increased threat sensitivity to facial cues and found that whereas participants were able to discriminate threatening from nonthreatening faces when fully rested, this ability was significantly reduced after 24 hours of sleep deprivation such that participants overestimated the level of threat from facial expressions.7
In a separate line of work, we also recently developed a social-evaluative decision-making task that requires individuals to rely on subtle facial cues to make decisions about an individual's potential trustworthiness.2 In this task, known as the Karolinska Airport Task (KAT), study participants are required to imagine that they are an airport security officer and must view a series of facial photographs and make a decision about whom to detain as a possible terrorist threat. Using the KAT, we found that among healthy individuals, those with higher levels of emotional intelligence were more likely to base trustworthiness decisions on subtle social cues reflected in facial features. We concluded that highly emotionally intelligent individuals were better able to perceive or incorporate these subtle facial features into decision making than those with lower emotional intelligence. In other words, individuals with lower emotional intelligence tended to make random decisions about the trustworthiness of each depicted individual, whereas those with higher emotional intelligence tended to detain only the most threatening-appearing passengers (according to prior ratings of the photographs made by other independent raters). At present, it is not known how implicit biases toward a particular minority group may also be associated with such explicit judgments about individuals more generally and how this relationship may be affected by restricted sleep.
In the present study, we aimed to follow up on our previous analyses by assessing whether sleep restriction impacts social-evaluative decision making about the trustworthiness of individuals based on subtle facial features using the KAT and how this may be associated with individual differences in implicit bias. It is possible that changes in implicit bias caused by sleep restriction are also associated with changes in explicit decision making. Based on prior work showing that perceptions of facial features of threat become particularly salient during sleep loss, we reasoned that those who show greater implicit biases as a result of restricted sleep would also show greater tendencies to base decisions on threatening facial features in the KAT.
In summary, the following research questions were examined:
- 1.
Does sleep restriction impact decisions about the trustworthiness of individuals based on subtle facial features?
- 2.
Do changes in implicit bias as a result of restricted sleep correlate with changes in decision making about the trustworthiness of individuals?
- 3.
Does sleep restriction amplify the strength of the relationship between implicit bias and explicit decision making about the trustworthiness of individuals?
Section snippets
Participants
Seventeen healthy young adults (8 women, 9 men; mean age = 24.53 years, SD = 4.20) completed a counterbalanced within-subjects crossover sleep restriction study. Subjects reported habitual sleep durations between 7 and 9 hours, with their regular habitual sleep period beginning within 1 hour of 11:00 pm. Some data from this sample have been reported elsewhere, including those for the IAT,1 but the associations with the KAT are novel and have never been reported. The exact inclusion and
Descriptive statistics
The mean number of detained individuals, and mean positive and negative character trait ratings for detained individuals for the sleep control and sleep-restricted conditions are displayed in Table 1. The total number of detained individuals was not significantly correlated with the mean positive or mean negative character trait ratings of detained individuals for the sleep control condition (negative: r = −0.43, P = .09; positive: r = 0.36, P = .16) or the sleep-restricted condition (negative:
Discussion
The aim of this study was to follow up on our previous finding that chronic sleep restriction led to increased negative implicit biases toward a particular minority group. Although it was clear from the previous work that sleep restriction led to increased biases, it was not clear whether this change would also be associated with explicit behavioral decisions in a socially relevant context. Therefore, the aims of the present follow-on analyses were to investigate (1) whether sleep restriction
Limitations
The results from this study should be interpreted with several limitations in mind. Whereas the IAT measured implicit biases toward Arab Muslim men, the KAT included only white European men and women. It is therefore difficult to make conclusions about implicit biases and explicit discriminating behavior generally or toward a specific minority group in particular. Future research would benefit from including a decision-making task that measures explicit discriminating behavior toward Arab
Conclusion
The results presented in this article may have implications for real-life situations where individuals in certain occupational specialties, such as police officers, airport security officers, and military personnel, have to make rapid decisions about people's trustworthiness almost entirely based on their physical appearance. It is not insignificant that individuals in such occupations are especially likely to be sleep restricted14 due to frequent shift-work schedules, long work days, or shifts
Conflicts of interest
The authors declare no conflicts of interest.
Acknowledgments
This work was funded by grants HL 105544 from the National Heart, Lung, and Blood Institute and grants UL1 RR02758 and M01-RR-01032 from the National Center for Research Resources to the Harvard Clinical and Translational Science Center.
References (19)
- et al.
National Sleep Foundation's updated sleep duration recommendations: final report
Sleep Health
(2015) - et al.
Sleep deprivation impairs recognition of specific emotions
Neurobiol Sleep Circadian Rhythms
(2017) Automatic associations and discrimination in hiring: real world evidence
Labour Econ
(2010)- et al.
Repeating patterns of sleep restriction and recovery: do we get used to it?
Brain Behav Immun
(2016) - et al.
The affect heuristic
Eur J Oper Res
(2007) - et al.
Neural basis of alertness and cognitive performance impairments during sleepiness II. Effects of 48 and 72 h of sleep deprivation on waking human regional brain activity
Thalamus Relat Syst
(2003) - et al.
Chronic sleep restriction increases negative implicit attitudes toward Arab Muslims
Sci Rep
(2017) - et al.
The role of emotional intelligence during an emotionally difficult decision-making task
J Nonverbal Behav
(2016) - et al.
Impact of total sleep deprivation on behavioural neural processing of emotionally expressive faces
Exp Brain Res
(2014)
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Author contributions: AA conducted the data analysis and wrote the manuscript. MH designed the study and collected the data. JS assisted in data analysis. RS, BCS, and AR contributed to writing of the manuscript. WDSK contributed to study design and writing of the manuscript.