Habitual (i.e., average or typical) sleep duration and sleep efficiency vary widely by demographic characteristics, including age, gender, and racial/ethnic identity. Despite a wealth of studies on demographic patterns in habitual sleep, these results are often based on cross-sectional surveys, which ask participants to retrospectively recall their "typical" or "recent" sleep. Yet, sleep is a highly dynamic behavior and may fluctuate substantially from night-to-night. This intraindividual variability (IIV) in sleep/wake patterns can be captured a multitude of ways, most commonly by using formula-based calculations. Although there is growing attention on the importance of IIV in sleep, findings on demographic differences are still inconclusive, and there are no guidelines for typical values of IIV in sleep. The present study quantitatively synthesized 8 international data sets (N = 2847 participants, 29,832 total days of sleep data), focusing on examining age, gender, and racial/ethnic identity differences in IIV in sleep measured via sleep diaries, actigraphy, and electroencephalography. Sleep duration and sleep efficiency varied widely from night-to-night within people (duration: 64-119 minutes; efficiency: 5-8%). Different metrics of IIV were strongly correlated within and across sleep measurement types. Younger adults had more IIV in diary and actigraphy sleep duration. Gender differences in IIV in sleep …

Breakups within emerging adulthood (EA) are associated with heightened distress because of individuals' tendency to be preoccupied by and prioritize romantic relationships. Global narrative scoring systems, such as Boals et al.'s meaning making (MM) and Feffer et al.'s interpersonal decentering, can be a useful for analyzing the activated cognitive processing in narratives about stressful events and have been linked to positive adjustment from those events. Attachment may moderate the benefits of processing a breakup. While avoidantly-attached people report lower breakup distress because of their tendency to suppress attachment-related thoughts and emotions, anxiously-attached individuals report prolonged distress due to their tendency to ruminate about the past relationship and to experience continued attachment to their ex-partner. The current study assessed the cross-sectional effects of MM and decentering on depression and breakup non-acceptance, as well as how attachment moderates the relationship between decentering and breakup adjustment. Results found higher MM was associated with higher depression and non-acceptance. More mature decentering was related to lower non-acceptance, but was unrelated to depression. Initial MM efforts may evoke more distress as individuals focus on distressing thoughts or emotions previously avoided. Initial decentering maturity may help with breakup adjustment as one effectively reflects on their own and …