How are humans motivated to copulate and reproduce? Are both males and females motivated into action to fulfil an innate biological need, which could in fact, be comparable to seeking out water when thirsty? Instead, could a strong psychological desire for physical intimacy be sufficient to provoke behaviour? Alternatively, could an individuals motivation be pulled along with the incentive of a rewarding and pleasurable experience: an orgasm? Arguably of most interest is how motives and incentives interplay to prompt behaviour. This blog will address the matter of how internal dispositions and environmental incentives direct the motivation of both males and females into the act of sexual intercourse, while addressing gender differences from an evolutionary perspective.
Sexual intercourse (SI) requires a high investment of precious resources from both parties, including; energy and time. The possibility that in forty weeks new life may enter the world would seldom be a strong incentive to move immediately, posits Deckers (2010.). Indeed a great number of psychological studies have shown that incentives are more powerful when the reward is available in the short term (see; Sutton & Barto, 1998; Gable & Berkman, 2013; Anselme, 2013). Deckers hypothesises that the reward for copulating is an orgasm, which is achieved upon consummation of the motivated behaviour. Deprivation of a biological need, such as food, has been shown to increase the reinforcing value of the reward (Raynor & Epstein, 2003). Kanin (1985) suggests that SI deprivation does increase the incentive value of the rewarding orgasm. However, males and females may not react in the same way to deprivation as Nelson and Morrison (2005) showed: The results indicated that male participants whom were deprived of food rated heavier women as more attractive than male participants who were satiated. The effect of deprivation had no effect on female preferences.
Gender differences also exist when comparing the likelihood of reaching orgasm during penile-vaginal SI. Males are statistically likely to orgasm close to 100% of the time, in contrast women orgasm 8% of the time (Lloyd, 2005). In a different study male participants were asked how to rate important it was for their female partner to reach orgasm, 90% of men rather it as very important (McKibbin, Bates, Shackelford & Hafen, 2010). Advances in the evolutionary theory of human mate selection provide a rational of perhaps why the female orgasm is so highly rated by men. Shackelford and Pound (2006) articulated that “sperm competition has likely been a recurrent adaptive problem for human males over evolutionary history” (p.47). An adaptive solution of ensuring her sexual appetite has been satiated, could impact the likeliness of the female copulating immediately or soon after SI.
Building a personal history that consists of mutually beneficial SI could act as an incentive to copulate again in the future. On average 65% of women admit to faking orgasms whilst having penile-vaginal SI. During the study the reasons given by women as to why they had faked an orgasm, was an awareness that she was not going to reach orgasm and lack of motivation to continue. (Muehlenhard & Shippee, 2010). The female orgasm, albeit real or fake, signals to the male that he should now ejaculate. Once ejaculation has taken place the SI will come to an end and the motivated behaviour is said to have reached its end-state.
The evidence presented illustrates the importance of a strong incentive in pulling motivation to end state. Moreover the incentive is most potent in times of deprivation, that is in males at the very least. However, it is unclear if orgasm as a reward is the motivating factor in females. Evidence suggests that females are motivated into SI by the incentive of an orgasm as shown in Shackelford and Pound’s (2006) research where women admitted to faked their orgasms; firstly they knew they would not climax, secondly that motivation had been lost. The findings suggest that once any possibility of the incentive is lost motivation diminishes. Personal history of SI must not be a strong enough incentive to reject copulation, as 92% of the time women fail to reach orgasm (Lloyd, 2005). It is argued that an orgasm during foreplay may actually be the incentive rather than during SI. However 90% of men rate a female orgasm during SI as important (McKibbin, Bates, Shackelford & Hafen, 2010), this is supported by the knowledge that sexually healthy men reserve their own orgasm until their partner has achieved theirs – or so he is lead to believe. It is therefore suggested that the male orgasm, and not the female orgasm, is the instrumental behaviour which consummates the motivated act of sexual intercourse.
Anselme, P. (2013). Dopamine, motivation, and the evolutionary significance of gambling-like behaviour. Behavioural brain research. 256, 1- 4. Abstract retrieved from http://www.sciencedirect.com/science/article/pii/S0166432813004385
Deckers, L. (2010). Motivation: Biological, psychological, and environmental. Allyn and Bacon.
Gable, S. L., & Berkman, E. T. (2013). Motives and Goals. Handbook of Approach and Avoidance Motivation. Psychology Press. Retrieved from http://books.google.co.uk/books?hl=en&lr=&id=vBkN4bimKAcC&oi=fnd&pg=PA203&dq=Motives+and+Goals.+&ots=S4XBSAXWCV&sig=YZxs271BI1z0rm9JtVYcRFnjqHs#v=onepage&q=Motives%20and%20Goals.&f=false
Kanin, E. J. (1985). Date rapists: Differential sexual socialization and relative deprivation. Archives of sexual behavior, 14(3), 219-231. Retrieved fromhttp://link.springer.com/article/10.1007/BF01542105#page-1
Lloyd, E.F. (2005) The Case of the Female Orgasm: Bias in the Science of Evolution. Cambridge, Mass.: Harvard University Press. Retrieved from http://books.google.co.uk/books?hl=en&lr=&id=6GFNvA6TvlwC&oi=fnd&pg=PA1&dq=The+Case+of+the+Female+Orgasm:+Bias+in+the+Science+of+Evolution&ots=OSOKrAOrWm&sig=ijdUp6y7H12BLEw_UtJ3D9bqMh0#v=onepage&q=The%20Case%20of%20the%20Female%20Orgasm%3A%20Bias%20in%20the%20Science%20of%20Evolution&f=false
McKibbin, W.F., Bates, V. M., Shackelford, T.K., LaMunyon, C.W., & Hafen, C.A. (2010). Risk of sperm competition moderates the relationship between men’s satisfaction with their partner and men’s interest in their partner’s copulatory orgasm. Personality and Individual Differences, 49, 961-966. Retrieved from http://www.sciencedirect.com/science/article/pii/S0191886910003958
Muehlenhard, C. L., & Shippee, S. K. (2010). Men’s and women’s reports of pretending orgasm. Journal of sex research, 47(6), 552-567. Retrieved from http://www.tandfonline.com/doi/abs/10.1080/00224490903171794#.UmfIfnCsjdo
Nelson, L. D., & Morrison, E. L. (2005). The Symptoms of Resource Scarcity Judgments of Food and Finances Influence Preferences for Potential Partners.Psychological science, 16(2), 167-173. Retrieved from http://pss.sagepub.com/content/16/2/167.short
Raynor, H. A., & Epstein, L. H. (2003). The relative-reinforcing value of food under differing levels of food deprivation and restriction. Appetite, 40(1), 15-24. Abstract retrieved from http://www.sciencedirect.com/science/article/pii/S0195666302001617
Shackelford, T. K., & Pound, N. (Eds.). (2006). Sperm competition in humans. New York: Springer. Retrieved from http://link.springer.com/chapter/10.1007/978-0-387-28039-4_1#page-1
Sutton, R. S., & Barto, A. G. (1998). Reinforcement learning: An introduction (Vol. 1, No. 1). Cambridge: MIT press. Abstract retrieved from http://www.citeulike.org/group/1070/article/112017