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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McKibbin, W. F., Goetz, A. T., Shackelford, T. K., Schipper, L., Starratt, V. G., & Stewart-Williams, S. (2007). Why do men insult their partners? Personality and Individual Differences, 43, 231-241.

Why do men insult their intimate partners?

William F. McKibbin a, Aaron T. Goetz a, Todd K. Shackelford a, Lucas D. Schipper a, Valerie G. Starratt a, Steve Stewart-Williams b

aFlorida Atlantic University
b McMaster University

 

Men sometimes insult their intimate partners and these insults predict intimate partner violence. No research has investigated the function of men’s partner-directed insults. We hypothesize that men’s partner-directed
insults are designed to retain their long-term mate and, therefore, that men’s use of partner-directed insults will covary with other mate retention behaviors. Using the mate retention inventory and the partner-directed insults scale, we conducted two studies to test this hypothesis. Study 1 included 245 men who reported their mate retention behaviors and partner-directed insults. Correlations and multiple regression analyses documented the predicted relationships between men’s partner-directed insults and mate retention behaviors. Study 2 included 372 women who reported their partner’s mate retention behaviors and insults that their partner-directed at them. The results replicated the results of Study 1. Discussion highlights future directions for investigating the relationships between men’s partner-directed insults and mate retention behaviors.

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Shackelford, T. K., Goetz, A. T., McKibbin, W. F., & Starratt, V. G. (2007). Absence makes the adaptations grow fonder: Proportion of time apart from partner, male sexual psychology, and sperm competition in humans. Journal of Comparative Psychology, 121, 214-220.

Absence Makes the Adaptations Grow Fonder: Proportion of Time Apart
From Partner, Male Sexual Psychology, and Sperm Competition
in Humans (Homo sapiens)

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

Florida Atlantic University

 

Sperm competition occurs when the sperm of multiple males concurrently occupy the reproductive tract
of a female and compete to fertilize an egg. We used a questionnaire to investigate psychological
responses to the risk of sperm competition for 237 men in committed, sexual relationships. As predicted,
a man who spends a greater (relative to a man who spends a lesser) proportion of time apart from his
partner since the couple’s last copulation reported (a) greater sexual interest in his partner, (b) greater
distress in response to his partner’s sexual rejection, and (c) greater sexual persistence in response to his
partner’s sexual rejection. All effects were independent of total time since the couple’s last copulation
and the man’s relationship satisfaction. Discussion addresses limitations of the current research and
situates the current results within the broader comparative literature on adaptation to sperm competition.

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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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