Apparently all societies around the world and throughout recorded history pursue one form of mysticism or spirituality or other if not full religions. For some, these can command central roles. The initial question is Why. Sociological, psychological, and even genetic "causes" have received the credit. And some evidence does commend each of these--once people started engaging in some form of religiosity. But why did people begin to engage in mysticism or spirituality in the first place? This question underlies Moffitt's investigation. Obviously direct evidence does not exist for events so far back in antiquity; and all contemporary societies/cultures (even the least technologically complex) are far too removed and complicated to use for scientific testing of hypothesis. Still, the species Homo Sapiens of several tens of millennia ago had a genetic system sufficiently like ours today for us to explore likely scenarios. The one proposed in Religiosity stems from the kinds of apparent miracles, extrasensory, out-of-body and near-death experiences that occur in common formats all over the globe regardless of culture. The author makes no judgement on the "reality" of these incidents. Whether or not they actually occur as reported is far less important to this analysis than the fact that so many people have believed and still believe them to be real. After all, our "real world" is what we perceive it to be. Religiosity then looks at such aspects as how the world's major religions deal diversely with certain beliefs and practices, such as fertility, life-after-death, ethics, deities, creation, asceticism, and sin. It examines several cases of societal response to traumatic crises (as from utter defeat in war, pestilence, and collapse of a strong religious system) to see how people react in their faith. The book also considers the implications of taking scripture either allegorically or literally as God's dictated words.