The internally driven, roughly 24-hour cycle of biological processes is a key concept in understanding human behavior and physiology. This cycle influences sleep-wake patterns, hormone release, body temperature, and other essential functions. For instance, the rise and fall of melatonin levels contribute to feelings of sleepiness and alertness throughout the day. External cues, such as sunlight, can influence or reset this internal clock.
Understanding this cycle is crucial for comprehending various psychological phenomena, including sleep disorders, mood disorders, and jet lag. Knowledge of its mechanisms allows for the development of interventions aimed at improving sleep quality, managing shift work schedules, and alleviating the symptoms of certain mental health conditions. Its investigation dates back to early observations of plant movements and animal behavior, eventually leading to sophisticated research on the molecular mechanisms underlying this internal timekeeping system.
