MorningnessEveningness

Morningnesseveningness, more commonly referred to as morningness-eveningness, is a dimension of human chronotype describing a person’s preference for timing of activity and alertness across the day. Individuals with high morningness prefer early wake times and tend to be most alert in the morning, while those with high eveningness prefer later wake times and peak later in the day. Most people fall along a continuum between these extremes.

Measurement is typically done with self-report questionnaires. The Morningness-Eveningness Questionnaire (MEQ), developed by Horne and Östberg, assigns scores that place individuals on a spectrum from eveningness to morningness. Other tools include the Munich Chronotype Questionnaire (MCTQ) and shorter screening measures. A range of biological, genetic, and environmental factors contribute to chronotype, including clock genes such as PER3 and CLOCK, age-related shifts in adolescence and aging, and light exposure.

Relationships and implications: Chronotype influences sleep timing, duration, and quality, and can affect daytime performance, mood, and health. Misalignment between biological propensity and social schedules—often called social jetlag—can contribute to fatigue and reduced cognitive efficiency. Morning types may have advantages for early-morning tasks, while evening types may struggle with early education or work start times. Chronotype also intersects with broader health outcomes, including metabolic and cardiovascular considerations, though causal links are complex and bidirectional.

Limitations: Morningness-eveningness is a spectrum shaped by biology and environment and is not a fixed label. It should be considered alongside overall sleep patterns and lifestyle factors.