Polygyny is accepted to varying degrees around the world. In some countries it is permitted by law (dark blue) or by customary law (medium blue). Or the law may permit polygyny if the marriage has been performed in another country (light blue). (Wikicommons)
In my last two posts I presented evidence that repeated exposure to porn desensitizes the male brain, eventually causing atrophy in those areas that process erotic stimuli. In addition, porn seems to influence psychosexual development differently in young European American males and young African American males.
If porn is virtual polygyny, the male brain should tolerate porn overload to the extent it has coevolved with polygyny. The threshold for desensitization would therefore be higher in cultures with generalized polygyny (20-50% of all marriages) and lower in cultures with limited polygyny (less than 10%).
The ‘virtual polygyny’ hypothesis was first put forward by Shepher and Reisman (1985):
Pornography creates a world of polygynous fantasy, in which there are always sufficient consenting females who unhesitatingly display their naked bodies, or body parts, thus signaling their preparedness for immediate sexual intercourse.
This fantasy world is very different from real life, especially where monogamy is the norm:
Of course, this fantasy world of unlimited numbers of young, beautiful, seductive females, eagerly and enthusiastically engaging in every sort of sexual and violent activity, contrasts sharply with everyday reality. (Shepher and Reisman 1985, p. 107)
It is even different from real life in polygynous cultures:
No power struggle, no competition between males for sexual access to a specific female is involved, because mass production makes the pornographic dream easily available to everyone. (Shepher and Reisman 1985, p. 108).
As a result, porn leads to desensitization and a desire for more and harder porn:
The result of fantasy-directed expectations may be a deterioration of male-female relationships, perhaps a deterioration of heterosexual comradeship and even love. Surely many males become disillusioned with their female partners' ability to arouse them. Any consistent use of pornographic magazines could also find readers thus disillusioned with their partners and their own sexual performance. The consequence for males may be, among other dysfunctions, conditional impotence. (Shepher and Reisman 1985, p. 110)
[...] habitual viewing often seems to result in a loss of arousal. We have found then, not illogically, that pornography is pushed to seek novelty: oral sex, anal penetration, sex with children, bestiality, pseudolesbianism, and sadistic sexuality. What this extension of repertoire tends to do to the male-female relationship is not difficult to imagine. (Shepher and Reisman 1985, p. 110)
[...] Arguably, as pornography use grows, male-female relationships deteriorate, aggression against women increases, sexuality is pushed towards more and more extravagant forms, more and more detached from sexuality's basic function in human life. (Shepher and Reisman 1985, p. 112)
Given that the incidence of polygyny varies considerably among human cultures, could some human populations be less vulnerable than others to porn desensitization? The two authors seem to raise this question:
Among 847 human cultures, 708 (83.4%) were found to condone polygyny, 137 (16%) monogamy, and 4 (0.47%) polyandry' (Murdock 1967). About half of the polygynous cultures permit polygyny, but actually not many males are married polygynously. The other half practices systematic polygyny.
This is a classic sample of coevolution: natural selection working on the individual favors polygyny; cultural selection working on the group favors monogamy. The most "successful" cultures, in the sense of their having the largest populations (Europe, the Americas, Japan, China, India), are monogamous, and most individuals in polygynous cultures are monogamous as well. (Shepher and Reisman 1985, p. 112)
Shepher and Reisman (1985) don't pursue this line of reasoning. One reason may have been the view, common in evolutionary psychology, that human nature has evolved very little since the Pleistocene. Because the high incidence of polygyny in sub-Saharan Africa is associated with agriculture (African hunter-gatherers have a very low incidence), and because agriculture began to develop there only some six thousand years ago (Vansina 1994), Shepher and Reisman might have concluded that the male brain never coevolved with generalized polygyny in sub-Saharan Africa. But why, then, the reference to coevolution? I suspect they simply floated this idea in the hope that someone else would pick it up. Or perhaps they had discussed this idea at greater length in their original manuscript ...
Shepherd and Reisman were writing in the 1980s, at a time when porn desensitization was probably much less common than it is today. Malamuth and Billings (1986, p. 93) reviewed the literature at that time:
Varied studies conclude that repeated exposure to erotica will, under many circumstances, result in less sexual arousal to and reduced interest in such materials. These studies include both experimental and survey research.
The first clear experimental study demonstrating habituation was conducted as part of the research of the commission [on Obscenity and Pornography] (Howard, Reifler, & Liptzin, 1971). This study found that repeated exposure of male college students to erotica for 90 min a day, 5 days a week for 5 weeks, resulted in a reduction in sexual arousal to erotic stimuli as well as reduced interest in such pornography. Following 2 months of nonexposure, however, there was a recovery in sexual arousal to levels that were not significantly different from those prior to the repeated exposure procedure [...]
Malamuth and Billings (1986) noted that this study had been criticized on the grounds that the levels of exposure were not "realistic." Today, such levels are common. According to a study of 16-year-old boys in two Swedish towns, 10% of them viewed porn every day, and about a third of these frequent users viewed porn for more than ten straight hours several times a week (Mattebo et al. 2013). In addition, young men are viewing porn for much longer than five weeks.
With the current high levels of porn consumption, more research is needed on the ‘virtual polygyny’ hypothesis, especially on its prediction that some human populations are more vulnerable than others to erotic desensitization and atrophy.
References
Malamuth, N.M. and V. Billings. (1986). The functions and effects of pornography: Sexual communications versus the feminist models in light of research findings, in J. Bryant and D. Zillmann (eds) Perspectives on Media Effects, Hillsdale, New Jersey: Erlbaum.
http://www.sscnet.ucla.edu/comm/malamuth/pdf/86PME_C5.pdf Mattebo, M., T. Tyden, E. Häggström-Nordin, K.W. Nilsson, and M. Larsson. (2013). Pornography consumption, sexual experiences, lifestyles, and self-rated health among male adolescents in Sweden, Journal of Developmental and Behavioral Pediatrics, 34, 460-468.
https://s3.amazonaws.com/academia.edu.documents/40260257/Pornography_Consumption_Sexual_Experienc20151122-22933-105aqic.pdf?AWSAccessKeyId=AKIAIWOWYYGZ2Y53UL3A&Expires=1508277205&Signature=diuNG%2BPn%2FznAqGmAlmlPKmFZ8mU%3D&response-content-disposition=inline%3B%20filename%3DPornography_Consumption_Sexual_Experienc.pdf Shepher, J. and J. Reisman. (1985). Pornography: A sociobiological attempt at understanding, Ethology and Sociobiology, 6, 103-114.
https://www.reuniting.info/download/pdf/Ethology_.pdf Vansina, J. (1994). A slow revolution: Farming in Subequatorial Africa, Azania: Archaeological Research in Africa, 29-30(1), 15-26.
http://www.tandfonline.com/doi/abs/10.1080/00672709409511658?journalCode=raza20