Goetz, A. T., Shackelford, T. K., Platek, S. M., Starratt, V. G., & McKibbin, W. F., (2007). Sperm competition in humans: Implications for male sexual psychology, physiology, anatomy, and behavior. Annual Review of Sex Research, 18, 1-22.

Sperm Competition in Humans: Implications for Male Sexual Psychology, Physiology, Anatomy, and Behavior

Aaron T. Goetz, California State University – Fullerton
Todd K. Shackelford, Florida Atlantic University
Steven M. Platek, University of Liverpool, UK
Valerie G. Starratt, Florida Atlantic University
William F. McKibbin, Florida Atlantic University


With the recognition afforded by evolutionary science that female infidelity was a recurrent feature of our evolutionary past has come the development of a new area of study within human mating: sperm competition. A form of male-male postcopulatory competition, sperm competition occurs when the sperm of two or more males concurrently occupy the reproductive tract of a female and compete to fertilize her ova. Just as males must compete for mates, if two or more males have copulated with a female within a sufficiently short period of time, the sperm from different males will compete for fertilizations. In the 2 decades since Smith (1984) first argued that sperm competition occurs in humans, this theory has been enriched with new ideas and discoveries. We review the recent theoretical and empirical work on human sperm competition, identify limitations and challenges of the research, and highlight important directions for future research.

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Starratt, V. G., Shackelford, T. K., Goetz, A. T., & McKibbin, W. F., (2007). Male mate retention behaviors vary with risk of sperm competition. Acta Psychologica Sinica, 39, 523-527

Male mate retention behaviors vary with risk of sperm competition.

Valerie G. Starratt, Todd K. Shackelford, Aaron T. Goetz, and William F. McKibbin

Florida Atlantic University


Sperm competition occurs when the sperm of two or more males concurrently occupy the reproductive tract of a single female and compete to fertilize an egg. This can be costly if the woman’s social partner loses the competition and, as a consequence, invests in offspring that are not genetically his own, a situation known as cuckoldry. Previous research suggests that men may have evolved tactics such as mate retention behaviors that reduce the risk of sperm competition and cuckoldry. The current research provides new evidence that men at greater risk of partner infidelity and sperm competition, measured as having spent a greater proportion of time apart from their partner since the couple’s last in-pair copulation, more frequently perform a variety of mate retention behaviors, such as calling unexpectedly to check up on their partners, monopolizing their partners’ time when around other men, and threatening other men who show an interest in their partners

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