In Religion for Realists, Samuel Perry lays out an argument for the necessity, even urgency, of the empirical study of religion. The author’s use of “we” in the book’s subtitle really does refer to everyone—not just academics, scientists, and scholars, but religious leaders, educators, and everyone else, religious or not. The author relies on survey data, sociological research, and personal experiences to make the case that the scientific study of religion has largely been ignored and marginalized, both within and outside the academy, and that if we can overcome our collective indifference and stop stigmatizing the people who study religion, and even the very idea of studying religion scientifically, society at large will benefit. If we maintain the status quo, the consequences could be dire, because those who do know how religion “really works” are also those who tend to use this knowledge to seek political gain, capitalize on prejudices, or promote other self-serving reasons.

The book uses six short chapters to make this argument. The first four focus on the misconceptions most Westerners hold about what religion is and how it works as a social phenomenon. For instance, there is the Anglo-Protestant bias of thinking of religion as organized sets of beliefs and rituals that owe whatever success they have to the power of ideas (chapter 1). The author argues that, to the contrary, religious ideas are downstream of the group dynamics, identity commitments, and social norms that structure human lives (chapter 2). Likewise, it is really population dynamics like birth rates and migration patterns (chapter 3), along with political realities, the strength of social safety nets, the nature of governments’ relationships to religion, and complex secularizing forces, among other things, that determine how and why people are religious (chapter 4). Throughout these chapters, the author briefly touches on and critiques topics familiar to sociologists, political scientists, and other scholars of religion—secularization theory, existential security, and the religious economies model—before turning in the last two chapters to a discussion of why research on religion is marginalized and what we should do about it.

It is hard to take issue with the idea that more effort on the part of more people to take religion seriously and to deepen our understanding of how it works in the contemporary world is a good thing. Religion has been and remains a potent force in society; more (and better) empirical examination is all but certain to yield important insights about what religion means for the twenty-first century. This aspect of the book’s premise is sound and is accompanied by a number of strengths. One is the argument for taking an ecological view over marketplace or “debate competition” theories for explaining religious growth and decline (p. 79). Another is the author’s demonstration of how, using the case of white evangelical Christians, the subordination of religious to political identities changes the nature of “conversion” and even what it means to be religious. Likewise, the points about the need for open science, more public-facing scholarship, and better communication of religious research are made well.

But a central argument of the first four chapters, namely that group identities precede religious ideas, is not without limitations. This claim is distilled in the author’s refrain, “we are bodies, then belongers, then believers” (p. 99). That we should always grant primacy to groups and reduce religious belief to issues of belonging and identity presents a lopsided picture of the complex dynamics of religion, both as a social phenomenon and as a matter of individual experience. To be sure, there are good reasons, sociologically, to put belonging ahead of everything else religion might offer. Religious ideas are indeed, in part, adaptive tools that emerge out of our need for belonging. But readers may be left with the impression that religion is really just about structural patterns of bodies in space playing in-group versus out-group games—and that religious beliefs are mere cognitive artifacts of these games, forever downstream of intrinsic human groupishness. Religious ideas, at most, serve only to symbolically express and rationalize collective experience.

But might this just reverse the equally dubious reasoning that religious beliefs always come first, and that we simply build identities and groups around those beliefs? Scholars should be slower to think in such linear terms. Ideas and identities are mutually reinforcing phenomena; there is no obvious reason to argue strictly that one is more important or has to come before the other. As many modern cognitive scientists argue, or as William James more than a century ago observed, religion also has cognitive and personal-experiential roots independent of group identity. Religious ideas have their own consequences and motivating capacities, psychological and emotional, that shape human lives and social arrangements. Belief in an afterlife, or in the resurrection of the dead, or in transmigration, is doing something more than merely shoring up group boundaries. Ideas are important to how “religion works,” and it is not necessary to reject or downplay this fact in order to make a compelling case for why we should, in many contexts, care more about bodies behaving in groups. As most students of religion have observed, the content of religious ideas can themselves produce conflict, shake up group norms, dissolve previous identity commitments, and even transform worldviews. Some discussion of this would not only have given a sense of balance but might have strengthened the author’s otherwise convincing argument about the pragmatic, social identity side of the religious equation, which undoubtedly involves tribal, partisan, and other boundary-making realities that characterize religious belonging. Of course, this is not to suggest scientists should be concerned with evaluating the truth of religious ideas. As Perry clearly states, this is not what it means for realists to study religion scientifically. But for a more complete picture, the scientific study of religion should also aim to understand the causes, characteristics, and consequences of religious ideas themselves, since they are not exclusively post hoc products of belonging to groups.

Another, more minor issue, is the author’s preference for the term “irreligious,” which is used many times without explanation. “Nonreligious” and “seculars” are also referenced a few times. These are not interchangeable words; they have different connotations, and there is scholarship in the field of secularity and nonreligion that deals with this. Nonreligious is descriptive and neutral, and simply refers to those who are not affiliated with or practice a religion. Irreligious, on the other hand, though it also refers to those who are not religious, has a more adversarial and negative connotation. Many (though not all) “nones” can be described as nonreligious, but they do not tend to take an oppositional stance toward religion, and many even hold religious and theistic beliefs. An atheist activist who routinely publicly decries religion? That is where irreligious is appropriate. Given the huge growth of the nonreligious in recent decades—they far outnumber the irreligious—and the implications this may have for society, it is not clear why the author made this semantic choice. But some definitions would have been in order, especially since the author does discuss secularizing trends and focuses so heavily on the roles of social identity and belonging in explaining how religion works.

Religion for Realists is a highly readable and interesting book that makes a timely and important argument. Each chapter offers something useful that should resonate with readers trying to understand the public role of religion, especially in these politically turbulent and uncertain times. The book is clearly written, jargon-free, and though it will still probably appeal mostly to those in the academy, it will likely have a wider audience than most monographs written by sociologists of religion. Although the author’s argument somewhat limits itself by being too narrowly focused on group identities, bodies and demographic trends in explaining how religion “really works,” the book does make an important contribution to the sociology of religion and will also have an impact beyond this discipline.