The Attraction of Religion is the first collection of essays to explore the connection between religion and sexual selection. According to the editors’ definition laid out in the introduction, the theory of sexual selection “argues that a number of traits and behaviors…evolved because they help to facilitate not survival per se but rather reproductive success by either making the individual attractive to the opposite sex or by deterring same-sex rivals” (2). Most of the remaining contributions use costly signaling theory to argue that religion supports reproductive success by facilitating cooperative behavior of some sort. Costly signaling in evolutionary theory means that some behavior (or perceptible trait) functions as a signal of an invisible or less apparent trait and is deemed reliable because it is too difficult (“costly”) to display unless the underlying trait is present. For example, a gazelle’s stotting signals its fitness to dissuade a predator from chasing it.
In his contribution, “Why Don’t Abstinence Education Programs Work?” James Van Slyke proposes that religion activates mating cognition associated with long-term mating strategies, increasing the effectiveness of monogamy while reducing conflicts resulting from male-male competition in a society. “Religion and Parental Cooperation,” by Joseph Bulbulia et al., presents an empirical study conducted in New Zealand that tests Jason Slone’s theory that religions evolved, at least in part, to support assessment of the qualities of potential mates. They suggest that women’s praying behavior in their homes sends signals of their faithfulness to men, and men’s church attendance sends signals to women of their social capital. Michael Blume, in contrast, presents evidence that people increasingly express religious behavior when exposed to pictures of attractive members of the same sex (rather than of the opposite sex). He analyzes the connection between religiosity and fertility in Swiss population data and proposes that religiosity sends signals to facilitate same-sex cooperation between women. Blume sketches a prehistorical scenario of women cooperatively raising children that would explain these observations.
In “Losing My Religion,” Jason Weeden refers to the empirical finding that religion, as measured in ninety countries, shows much greater correlation with reproductive morals than with morality in general. Elaborating on the “reproductive religiosity model,” he proposes that participating in religious groups is a tool for high-commitment, high-fertility lifestyles. He also notes that parental involvement in church encourages such a lifestyle choice in children. Craig Palmer and Ryan Begley discuss the problem of parental influence further in their contribution entitled “Costly Signaling Theory, Sexual Selection, and the Influence of Ancestors on Religious Behavior.” The authors suggest that the explanation of religion has to consider the role of religious traditions in encouraging cooperation between relatives, which they understand in the framework of inclusive fitness. (Inclusive fitness accounts for altruism toward related individuals with whom one shares a great part of one’s genome.) Altruism toward other members within the linage favors the long-term propagation of the ancestors’ genes (carried by their descendants), whereas it is not always in the interest of the descendants themselves.
In “When Religion Makes It Worse,” Yeal Sela, Todd Shackelford, and James Liddle make a case for the use of religion as a tool of aggression in sexual selection. They note that both intrasexual aggression between men and various forms of intersexual aggression by men toward women provide males with a reproductive advantage. They cite examples from (Abrahamic) religious traditions to show how religion contributes to mate guarding (that is, male’s controlling of mating partners). Out of the remaining contributions, only David Bell’s chapter “Fathering, Rituals, and Mating” deals directly with sexual selection. Bell observes the uniqueness of men’s contribution to childrearing among mammals and suggests that religion supports paternal bonding with children and provides a channel to pass on related behaviors to the offspring. The use of religion to advertise fitness is the topic of both “The Dividends of Discounting” by Matthew Martinez and Pierre Liénard and also Panagiotis Mitkidis and Gabriel Levy’s “False Advertising.” Finally, in “The Evolutionary Psychology of Theology,” Andrew Mahoney suggests that the human tendency to acquire theology (defined as complex supernatural knowledge) evolved to support organization and cooperation.
Taken together, the studies make a case for a likely connection between religion and sexual selection. What this link entails, however, remains unclear, not least because the suggestions made by individual contributions are often mutually contradictory. It is noticeable that differences in the proposed solutions often result from differences in the respective populations from which empirical evidence is derived. The strongly patriarchal tendencies of traditional Abrahamic religions (from which the majority of the data cited in the contributions comes) can explain why women who participate in these religions have more children than women who do not. But the patriarchal nature of these religions might simply reflect the patriarchal values of the cultures that shaped them in historical time, rather than the evolved function of religion in general. It is quite possible that in Western-type democracies people who hold patriarchal values to begin with adhere to such religions in greater numbers than do people who do not hold such patriarchal values.
Insofar as theorizing on religion and sexual selection aims at explaining the evolutionary link between these two domains, it is necessary to look beyond Abrahamic religions and contemporary settings. Although it is difficult to make definitive conclusions about prehistorical marriage systems, existing studies suggest that neither courtship nor monogamy, two assumptions that most of the studies in this volume make, were characteristic of the ancestral condition. Finally, let us note that sexual selection is usually understood in broader terms than only signaling attractiveness (toward the opposite sex) or deterrence (toward the same sex), as suggested by the introduction to this volume. Sexual selection has shaped such diverse traits and behaviors as social cognition, the anatomy of reproductive organs, the life cycle, muscle mass, fighting and intercepting abilities, deceptive skills, and spatial cognition, which invites further theorizing about the nexus between sexual selection and the rich cognitive and behavioral complex we call religion.
Istvan Czachesz is Professor in the Department of History and Religious Studies at the University of Tromsø.
Istvan Czachesz
Date Of Review:
December 12, 2016