Related Experiment Video
Updated: Aug 11, 2026

Observation and Quantification of Mating Behavior in the Pinewood Nematode, Bursaphelenchus xylophilus
Published on: December 25, 2016
Seasonality of first coitus in the United States
J L Rodgers1, D F Harris, K B Vickers
1Department of Psychology, University of Oklahoma, Norman.
Abstract:
Recent attention to causes of seasonality of births leads to an interest in seasonality patterns in the antecedents to birth, including gestational length, conception, and coital activity. In this paper we study the beginning of the process: first intercourse among adolescents and young adults. Analysis of a small and local dataset is suggestive that loss of virginity is particularly likely during the summer. A test of this "Summer Vacation Theory" using a large national dataset supports the generality of the phenomenon. Further, a prediction that seasonality patterns will change during the transition from high school to work and college is tested and supported. The existence of both biological and psycho-social mechanisms is suggested. Policy implications are reviewed.
More Related Videos
Related Concept Videos
Cross-Sectional Research
Biological Clocks and Seasonal Responses
The Ratio of X Chromosome to Autosomes
Normal male Drosophila has a ratio of one X chromosome to two sets of autosomes. In contrast, normal female Drosophila...
Ovarian Cycle
Amebiasis
Trichomoniasis

