The Strange Link Between Attitudes Towards Sex and Drugs
Preferred mating strategies may influence attitudes to recreational drugs
Posted Sep 17, 2016
According to recent research in evolutionary psychology, people’s attitudes towards recreational drug use are linked to their attitudes towards sexual promiscuity. According to this view, recreational drug use is generally perceived as fostering sexual promiscuity. Hence, those who disapprove of promiscuity tend to disapprove of recreational drug use, while those with more permissive sexual attitudes tend to be more permissive towards drug use. If this view is correct, it implies that social and environmental factors conducive to promiscuity are also likely to be conducive to more permissive attitudes towards drugs.
Recreational drug use is a divisive issue that evokes strong emotional reactions that are often out of proportion to the seriousness of the topic, sometimes rising to the level of moral panic. Many people strongly condemn drug use and believe that people should be punished for engaging in it, even if they are not actually harming anyone else in the process. Evolutionary psychologists have noted that this is an example of a larger pattern wherein people insist that costs be imposed on people who engage in certain behaviours, even when these do not harm others (Kurzban, Dukes, & Weeden, 2010). Kurzban and colleagues note that activities that harm other people, like murder and theft, tend to be universally condemned. On the other hand, when it comes to drug use, there is much more variation in people’s moral attitudes to the subject, and many people even disagree about whether it is a moral issue at all. For example, surveys have found that a large proportion of the US population currently favours legalization of marijuana, while many others strongly oppose it. People may justify condemning drug use as a way of protecting others from harm. However, many potentially harmful activities are not condemned in this way, e.g. risky sports and even riskier occupations.
A number of different theories have been developed to understand why there is so much variation in people’s views on this topic, and why it evokes such strong feelings. According to the standard social science view, people develop commitments to abstract political ideologies through social learning and form emotional attachments to these abstract factors. Views on drugs then flow from these commitments. In this view, self-interest is rarely a strong influence on political attitudes compared to symbolic political commitments.
An alternative view, developed from an evolutionary psychology perspective, is that differences in people’s preferred reproductive strategies influence their views on other issues in ways that reflect their strategic self-interests. More specifically, some people prefer a strategy involving long-term commitment to a single partner, whereas others prefer a more promiscuous lifestyle. People who prefer monogamy feel threatened by promiscuity, because when people in one’s community are promiscuous there may be a greater risk that sexual rivals will try to tempt one’s partner into infidelity. On the other hand, those who prefer promiscuity would prefer that many other people have a similar preference so that they will have more sexual opportunities. There is evidence that recreational drug use actually is linked with greater sexual promiscuity in both men and women, although so are alcohol use and tobacco smoking (Zuckerman & Kuhlman, 2000), so from an evolutionary perspective it makes a kind of sense that people tend to either condemn or condone drug use based on their preferred reproductive strategy.
Two published studies have provided support for this theory (Kurzban et al., 2010; Quintelier, Ishii, Weeden, Kurzban, & Braeckman, 2013). In a series of five studies, participants were asked about their attitudes to the morality and legal status of recreational drugs, such as marijuana, cocaine, and ecstasy, as well as sociosexuality (willingness to engage in casual and uncommitted sex), their political views (i.e. how generally liberal or conservative they were, as well as their views on a number of specific issues), and how religious they were. Additionally, they completed brief measures of the Big Five personality traits. Across all five studies, attitudes towards recreational drug use were most strongly related to sexual attitudes. Specifically, people who agreed with statements like, ‘Sex without love is OK,’ and ‘I can imagine myself being comfortable and enjoying “casual” sex with different partners,’ and who approved of internet pornography had more favourable attitudes towards recreational drug use. Furthermore, the associations between sexual attitudes and views on drugs remained strong even when controlling for non-sexual variables, such as religiosity, political conservatism, and personality. On the other hand, for the most part, non-sexual variables were not significantly associated with views on drugs when controlling for sexual variables (exceptions tended to be inconsistent across studies). These relationships were found in a sample of US students, and an internet sample (Kurzban et al., 2010), as well as in samples from Belgium, the Netherlands, and Japan (Quintelier et al., 2013). These results suggest that sexual attitudes may be more fundamentally relevant to people’s views on drug use than their general political ideology, in line with the theory that people uphold views that support their reproductive interests.
Evolutionary psychologists have proposed a number of theories to explain why people differ in their preferred reproductive strategies. Strategic pluralism theory suggests that monogamy might be most adaptive in harsh unpredictable environments because children have a better chance of surviving when their parents are in a committed relationship. On the other hand, in more benign environments, sexual promiscuity might become more attractive. This theory is supported by findings that wealthier developed countries have higher rates of sociosexuality than poorer developing countries (Schmitt, 2005). Another theory suggests that imbalanced sex ratios influence reproductive strategies. Specifically, when there are more men than women available for marriage in a community, men compete more intensively with each other for mates, and women can demand greater relationship exclusivity from potential mates. Conversely, when there are more women than men, competition for mates will be more intense between women, who become more willing to satisfy men’s desires for short-term mating. This is supported by a US study that found that regional variation in sociosexuality was associated with imbalanced sex ratios (Kandrik, Jones, & DeBruine, 2015). Another, more complex theory suggests that women who are vulnerable to infectious diseases may become more interested in sexual variety when they feel threatened by disease (Hill, Prokosch, & DelPriore, 2015). The idea is that women who are vulnerable to disease may try to increase the odds that their offspring will have immunity to whatever diseases are prevalent in one’s environment. One way of doing this, is to have children with a number of different sexual partners as each one will contribute a different set of genes, and hence a different set of immune responses to disease. This intriguing theory has been supported by studies by Hill and colleagues that found that when women were led to believe that infectious were on the rise in society, those who reported having a history of vulnerability to disease expressed a desire for a greater number of lifetime sexual partners than healthier women.
If it is the case that attitudes to recreational drug use are influenced by preferred reproductive strategies, then it seems reasonable that the same factors that influence the latter could also influence the former. Hence, one might expect that drug attitudes might be more conservative in harsh unpredictable environments, such as in developing countries, and more permissive in more benign environments such as developed nations. I have not been able to find any surveys directly comparing drug attitudes across different countries, but this would make an interesting test of the theory. According to the World Values Survey, as countries become more prosperous, their cultural values tend to shift from those emphasising survival to self-expression values stressing autonomy, freedom, diversity, and creativity. Countries with stronger self-expression values tend to have more permissive sexual mores. Furthermore, condemnation of drug use seems more characteristic of survival than self-expression values.
Similarly, if the sex ratio theory holds, one could expect that imbalanced sex ratios in a community could influence attitudes to recreational drug use. This could be tested by comparing survey responses from people in areas with differing sex ratios. Perhaps it might even be possible to test this experimentally. For example, people could be asked to imagine moving to a new community that has either more men than women, or vice versa. Then they would be asked to imagine that a proposal is made in this community to decriminalize soft drugs, and then to state how strongly they would support or oppose such a proposal. In a community with more men than women, one might expect greater condemnation of drug use, while in a community with more women than men, there might be more support for decriminalization.
The vulnerability to disease theory could be tested using much the same methods that Hill and colleagues used. That is, groups of women could be primed with disease threat; if the theory holds, women with a history of vulnerability to disease might then express more support for permissive drug policies such as decriminalization than other women.
The decades long “War on Drugs” has had very destructive social consequences that arguably have been more disastrous than the impact of drug use itself, and even many conservative thinkers have declared it a failure. Better understanding of why some people condemn, while others oppose recreational drug use, might not only provide insight into a fascinating area of human behaviour, but might also help foster more enlightened, more humane social policies.
 Robert Anton Wilson used to sardonically refer to this as “the war on some drugs.”
© Scott McGreal. Please do not reproduce without permission. Brief excerpts may be quoted as long as a link to the original article is provided.
The Smokers by Adriaen Brouwer, 1636
Le Déjeuner sur l'herbe (Luncheon on the Grass) by Édouard Manet, 1863
Hill, S. E., Prokosch, M. L., & DelPriore, D. J. (2015). The Impact of Perceived Disease Threat on Women's Desire for Novel Dating and Sexual Partners: Is Variety the Best Medicine? Journal of Personality & Social Psychology, 109(2), 244-261.
Kandrik, M., Jones, B. C., & DeBruine, L. M. (2015). Scarcity of female mates predicts regional variation in men's and women's sociosexual orientation across US states. Evolution and Human Behavior, 36(3), 206-210. doi:http://dx.doi.org/10.1016/j.evolhumbehav.2014.11.004
Kurzban, R., Dukes, A., & Weeden, J. (2010). Sex, drugs and moral goals: reproductive strategies and views about recreational drugs. Proceedings of the Royal Society of London B: Biological Sciences.
Quintelier, K. J. P., Ishii, K., Weeden, J., Kurzban, R., & Braeckman, J. (2013). Individual Differences in Reproductive Strategy are Related to Views about Recreational Drug Use in Belgium, The Netherlands, and Japan. Human Nature, 24(2), 196-217. doi:10.1007/s12110-013-9165-0
Schmitt, D. P. (2005). Sociosexuality from Argentina to Zimbabwe: a 48-nation study of sex, culture, and strategies of human mating. Behavioral and Brain Sciences, 28, 247-311.
Zuckerman, M., & Kuhlman, D. M. (2000). Personality and Risk-Taking: Common Bisocial Factors. Journal of Personality, 68(6), 999-1029. doi:10.1111/1467-6494.00124