Cultural evolution favors religious groups that maximize reproduction

Evidence

However, I hope it is clear by now that in the logic of cultural evolution, there is no reason to expect that all religious groups reproduce at high levels. The logic is simply that those religious groups with beliefs and practices that promote population growth (be it by conversions, or higher fertility rates, or both), all else being equal, would outcompete their rivals—including religious rivals like the Shakers and the self-castrating Skoptsy—and take a larger share of the religious market, and ultimately the world’s population. — Norenzayan, Ara, Big gods - how religion transformed…, 499

Categorization

• XREF: Selection-of-groups logic parallels the Big God fitness argument feeding the reader’s survival/outcompete model.
• BMF: The Skoptsy and Shakers as ascetic groups that outbreed themselves evokes the excesses of self-denial mirrored in We’s anti-individualist zeal — a group whose own logic drives it toward extinction.