First-night effect causes reduced sleep in unfamiliar environments

Sleep researchers have identified a phenomenon known as the ‘first-night effect,’ which causes individuals to sleep less deeply and for shorter durations when in an unfamiliar environment. Studies suggest that on average, people sleep 20 to 30 minutes less during their first night in a new location.

Experts from the University of Freiburg and the University of Pittsburgh suggest the effect has evolutionary roots. The brain may remain in a state of heightened vigilance to protect the individual from potential dangers in an unknown setting. Research indicates that the frontal lobe, which is typically active during deep sleep, remains more active during the first night in a new place, acting similarly to how certain animals maintain partial brain alertness while sleeping.

Age plays a significant role in the severity of the effect; it is most pronounced in children, adolescents, and older adults, while individuals in their 20s appear to be the least affected. While the effect typically fades after the first night as the environment becomes familiar, other factors such as travel fatigue, environmental disturbances, and psychological stress can also impact sleep quality.