News Release

Study shows college students have less empathy when they are less alert

Study finds that changes in alertness may undermine an individual’s ability to empathize

Reports and Proceedings

American Academy of Sleep Medicine

DARIEN, IL – A new study to be presented at the SLEEP 2024 annual meeting found robust evidence that implicates lower alertness, a key outcome of insufficient sleep, as a predictor of muted empathic responding, which suggests alertness may support both cognitive and affective empathy.

Results show that slower response times on objective alertness tests were significantly associated with lower levels of empathic concern, and that lapses and false starts on these tests were significantly associated with poorer empathic accuracy. Additionally, those who were more objectively alert reported significantly higher affective empathy than the control group.

“Affective empathy is the ability to feel emotions in concordance with another, and cognitive empathy is the ability to understand what another is feeling,” said lead author Breanna Curran, who is a psychology graduate student at Iowa State University in Ames, Iowa. “Slightly less alert individuals exhibited muted affective empathy, while only individuals who exhibited attention lapses exhibited poorer cognitive empathy.”

Sufficient, healthy sleep is associated with better health outcomes, including improved attention, behavior, learning, memory, emotional regulation, quality of life, and mental and physical health. The American Academy of Sleep Medicine and Sleep Research Society recommend that adults should sleep 7 or more hours a night on a regular basis to promote optimal health.

The researchers collected data from over 800 college students across three studies. In all three studies, participants first reported on their subjective alertness using the Karolinska Sleepiness Scale, and their objective alertness was measured using the Psychomotor Vigilance Test. Participants then completed the Multifaceted Empathy Test to measure cognitive and affective empathy. Study 2 replicated Study 1 using more diverse stimuli, and in Study 3 participants were randomly assigned to ingest 300 mg of caffeine or a placebo before completing the tasks. All participants then completed an additional affective empathy test.

Curran noted that the relationship between alertness and both an individual’s empathic accuracy and concern helps us to better understand the driving mechanism behind why sleep disruption harms an individual’s ability to empathize.

“In an applied setting, this novel finding can aid understanding of an individual’s lack of empathy and can inform recommendations for those whose empathy is essential to their occupation,” Curran said.

The research abstract was published recently in an online supplement of the journal Sleep and will be presented Tuesday, June 4, during SLEEP 2024 in Houston. SLEEP is the annual meeting of the Associated Professional Sleep Societies, a joint venture of the American Academy of Sleep Medicine and the Sleep Research Society.


Abstract TitleThe Role of Alertness in Cognitive and Affective Empathy

Abstract ID: 0129

Poster Presentation Date: Tuesday, June 4, from 11-11:45 a.m. CDT, Board 62

Presenter: Zlatan Krizan, Ph.D.

Authors: Breanna Curran, Anthony Miller, Zlatan Krizan

About the Associated Professional Sleep Societies, LLC

The APSS is a joint venture of the American Academy of Sleep Medicine and the Sleep Research Society. The APSS organizes the SLEEP annual meeting each June (

About the American Academy of Sleep Medicine

Established in 1975, the AASM advances sleep care and enhances sleep health to improve lives. The AASM has a combined membership of 12,000 accredited sleep centers and individuals, including physicians, scientists and other health care professionals who care for patients with sleep disorders. As the leader in the sleep field, the AASM sets standards and promotes excellence in sleep medicine health care, education and research (

About the Sleep Research Society 

The SRS is a professional membership society that advances sleep and circadian science. The SRS provides forums for the exchange of information, establishes and maintains standards of reporting and classifies data in the field of sleep research, and collaborates with other organizations to foster scientific investigation on sleep and its disorders. The SRS also publishes the peer-reviewed, scientific journals Sleep and Sleep Advances (

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