Original article:

Semen displacement as a sperm competition strategy in humans

Evolutionary Psychology 2: 12-23 Gordon G. Gallup, Department of Psychology, State University of New York at Albany, Albany, NY 12222, USA, gallup@albany.eduRebecca L. Burch, Department of Psychology, State University of New York at Oswego, Oswego, NY 13126, USA, rburch@oswego.edu


We examine some of the implications of the possibility that the human penis may have evolved to compete with sperm from other males by displacing rival semen from the cervical end of the vagina prior to ejaculation. The semen displacement hypothesis integrates considerable information about genital morphology and human reproductive behavior, and can be used to generate a number of interesting predictions.


penis morphology, semen displacement, sperm competition, sperm retention, premature ejaculation, double mating, circumcision, penile hypersensitivity, refractory period, fertilization by proxy, last male precedence, infertility, self-semen displacement, semen coagulation, wife rape

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Evolutionary Psychology - An open access peer-reviewed journal - ISSN 1474-7049 © Ian Pitchford and Robert M. Young; individual articles © the author(s)

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