Biological explanations of crime began to wane in the early decades of the twentieth century as sociologists introduced concepts such as social disorganization, anomie, strain, learning, and control to the discipline of criminology (discussed in Chapter 4). The sociological theories were more in line with and built upon the classical school, reverting partially back to the original attempts at understanding and responding to crime.

By the second half of the twentieth century, criminal anthropology and other fields (e.g., phrenology) were discredited and mocked as pseudoscience. It was not until the final decades of the twentieth century that biological explanations became relevant once again, this time using more sophisticated methods and tools. Some of these newer theories on intelligence and personality style will be discussed in Chapter 5.

Attempts to identify biological and hereditary explanations of crime remain both intriguing and controversial. Current research in these areas emphasizes the notion of “nature via nurture” as opposed to “nature versus nurture” of earlier studies. The nature versus nurture debate tries to tie the blame for criminal behavior (among other characteristics) to either genetics (nature) or the way in which someone was raised (nurture). The nature via nurture argument states that both genetics and environment form who someone turns out to be and how they choose to behave. In contrast to the determinism of the original biological positivists (people are born “criminal” and nothing can be done to change that), today’s researchers emphasize that biology interacts with and is influenced by the broader environment. This research remains controversial and continues under careful scrutiny.