Killgore William D S
Division of Psychiatry and Neuroscience, Department of Behavioral Biology, Walter Reed Army Institute of Research (WRAIR), 503 Robert Grant Avenue, Silver Spring, MD 20910, USA.
Psychol Rep. 2007 Apr;100(2):613-26. doi: 10.2466/pr0.100.2.613-626.
Individuals differ along a continuum of preference for diurnal activity level, known as Morningness-Eveningness. Individuals low in Morningness traits, i.e., preferring later awakening and bed times, have been shown to score higher on personality traits of impulsiveness and novelty-seeking. No studies have yet examined the association between Morningness-Eveningness and the related construct of risk-taking. Therefore, the present study examined (1) whether Morningness was correlated with self-reported and behavioral measures of risk-taking, and (2) whether one night of sleep deprivation would produce changes in risk-taking and sensation-seeking. 54 healthy adults were administered the Morningness-Eveningness Questionnaire at intake, and administered the Brief Sensation Seeking Scale, Evaluation of Risks Scale, and Balloon Analog Risk Task at rested baseline, again following 23 hr. of sleep deprivation, and finally after a 12-hr. period of recovery sleep. Lower Morningness scores were associated with higher self-reported total risk-taking propensity when rested (p< .05) and sleep deprived (p<.005), but correlations were not significant for sensation seeking or actual risk-taking behavior. Relative to baseline and postrecovery periods, sleep deprivation significantly reduced risk-taking propensity, including self-report indices of self-control, danger-seeking, energy level, and sensation-seeking, and behaviorally measured risk-taking. Chronotype did not interact with sleep condition for any of the dependent variables, although Evening Types scored higher on several indices of risk-propensity. Findings suggest that Morningness traits are inversely related to greater risk-taking propensity, while sleep deprivation significantly reduces self-reported and behaviorally demonstrated willingness to engage in high-risk and sensational activities under conditions of uncertainty, regardless of chronotype.
个体在对日间活动水平的偏好连续体上存在差异，这被称为晨型-夜型。晨型特质得分低的个体，即更喜欢晚起和晚睡，已被证明在冲动性和寻求新奇的人格特质上得分更高。尚未有研究考察晨型-夜型与冒险相关构念之间的关联。因此，本研究考察了：（1）晨型是否与自我报告的冒险测量和行为测量相关；（2）一晚睡眠剥夺是否会导致冒险和感觉寻求的变化。54名健康成年人在入组时接受了晨型-夜型问卷，在休息基线时、睡眠剥夺23小时后以及12小时恢复睡眠后，分别接受了简版感觉寻求量表、风险评估量表和气球模拟风险任务。较低的晨型得分与休息时（p<0.05）和睡眠剥夺时（p<0.005）较高的自我报告总冒险倾向相关，但感觉寻求或实际冒险行为的相关性不显著。相对于基线期和恢复后期，睡眠剥夺显著降低了冒险倾向，包括自我控制、寻求危险、能量水平和感觉寻求的自我报告指标，以及行为测量的冒险。尽管夜型在几个风险倾向指标上得分较高，但对于任何因变量，时间类型与睡眠状况之间均无交互作用。研究结果表明，晨型特质与更高的冒险倾向呈负相关，而睡眠剥夺显著降低了在不确定条件下自我报告的和行为表现出的参与高风险和刺激性活动的意愿，无论时间类型如何。
