Is and Ought? Problems with Deriving “Natural” and Prescribing “Normal” via the Human Evolutionary Record

There is a strong entanglement between the evolutionary history of any given lineage of organisms and assumptions about the “nature” of those organisms. Humans evolved, and continue evolving, and thus our evolutionary history shapes much of who and how we are. However, humans are also diverse, complex, fascinating, and biocultural, and there is no one specific ecology, society, or behavior that epitomizes all of humanity. Thus, interpretations of the human past, and assumptions about the human present, often straddle the boundaries between “is,” a descriptive approach of the available data and analyses on human evolution, and “ought,” a proscriptive assertion about how humans truly are and thus should be. Many biases in understandings of the past and of evolutionary processes lead to flawed reconstructions of human evolutionary history and promote misconceptions, “oughts,” about human behavior and societies. Highlighting a suite of data and analyses from the study of Pleistocene Homo that illustrate a range of variation, including complexity in reproducing and caretaking, and multifarious, malleable intergroup relations across space and time, can offer a corrective to common misconceptions. This chapter reviews current knowledge of Pleistocene Homo and the human niche, offering two examples of what the human evolutionary record can and cannot inform us about becoming and being human. The examples are: intergroup relations and xenophobia, and the core social structures around child-rearing.