Time for sex: nycthemeral distribution of human sexual behavior

Abstract

BackgroundNycthemeral (daily) oscillation has been documented in a variety of physiological and behavioral processes. The present study was carried out to evaluate the existence of a nycthemeral rhythm of human sexual behavior and to identify environmental factors responsible for the rhythmic pattern.MethodsNon-traditional university students (ages 18 to 51 years) recorded the times of day when they went to sleep, when they woke up, and when they had sex for 3 consecutive weeks. They also answered a questionnaire designed to identify the causes of their selection of time for sex.ResultsThe majority of sexual encounters took place at bedtime (11 pm to 1 am). The most common explanations for this temporal pattern were the rigidity of the professional work schedule and family obligations and the availability of the partner, which reduced the opportunity for sexual encounters at other times of the day.ConclusionMost sexual encounters take place around bedtime. Although the presence of an endogenous component responsible for this temporal pattern cannot be excluded, the evidence indicates strong environmental forcing, particularly from the work/family schedule of the individuals and from partner availability.

Chronotype, gender, and time for sex

“…The observed patterns could be related, for example, to day schedules such as starting work activities, caring for the children, and primarily to the presence of a sexual partner as suggested previously (Refinetti, 2005). The latter issue might be of special importance for occurrence of evening peak in sexual activity, particularly in subjects not living with their sexual partners, as in the case of most participants in this study.…”

“…Moreover, it is not known whether there are differences between the chronotypes in the timing of need for sexual activity. The timing of need for sexual activity and actual undertaking of sexual activity might be different considering that, in a previous study, subjects explained their choice of time for sexual activity by partner availability than by actual desire (Refinetti, 2005). We also aimed to explore gender differences in preferred time of day for sexual activity, as no such direct comparison has been reported so far -previous studies have considered mostly pairs with no distinction on gender.…”

“…In a study on 15 university students (Refinetti, 2005), the majority of sexual encounters took place between 23:00 and 01:00 at night, while a secondary, smaller peak occurred in the morning at 6:00 -8:00. Participants explained that the main reason they choose that time for sexual activity was partner availability (around bedtime).…”

Why Do Healthy Men Experience Morning Erections?

“…In general, the majority of sexual encounters take place at bedtime, that is, people begin to sleep after having sex, while some of the encounters do occur during the daytime [45]. However, approximately 20% of sexual encounters take place early in the morning [46].…”

Circadian rhythms and reproduction

“…A delay in insemination for 4-6 h following ovulation can significantly impair the viability of embryos in mice (Sakai & Endo 1988). In humans, there is a strong circadian component to intercourse, with the major peak of sexual activity in the late night (Palmer et al 1982, Refinetti 2005) and a minor peak in the early morning, especially on weekends (Palmer et al 1982). Humans are probably unique in copulating throughout the ovarian cycle and to our knowledge, no studies have been conducted to determine whether the time of day of intercourse in relation to the time of day of ovulation alters fertility outcomes.…”