Wachbroit, Robert (2006). “Normality and the Significance of Difference” in Parens, Eric, Chapman, Audrey R, and Press, Nancy (eds.) Wrestling with Behavioral Genetics. Baltimore: Johns Hopkins University Press, 235-53.
Wachbroit argues that current investigations into human genetics do not seem capable of identifying the essential properties of being human. Genetic discoveries will affect our conception, which is directly related to how we understand “normal”. The more we learn about the genetic causal factors of various conditions the more explanatory language will be in genetic terms. What constitutes normality of health will be reassessed medically and socially. Discoveries in the fields of medicine and psychology in relation to genetics will alter out understanding of normality and how we conceptualize others and ourselves. Normality may be defined as:
1. A mathematical concept.
2. An evaluative concept.
3. A biological concept.
Mathematical normality is understood to refer to the mean, median, or mode of a distribution. The Bell Curve, Gaussian distribution, and Normal Curve are roughly equivalent and examples of normality in mathematics. Evaluative normality refers to conventional, cultural, institutional, and ethical norms. Less precise and more subjective than mathematical normality, evaluative norms are often context specific, as one type of behavior in one cultural setting may not be considered normal in another. Biological normality refers to the language that biologists, physicians, or psychologist use to refer to a biological unit such as an organ, a physical reaction, or an environment a person experiences. For example, "You have a normal heart", "Her vital signs were normal", or "He had a normal childhood" all refer to a biological concept of normality.
The biological concept of normality is problematic because it refers to the subjective meaning of 'healthy' and may not point to the average, majority, or ideal. When a physician says that a patient has a normal heart she is not referring to the average heart because that is epistemologically impossible. Secondly, when a psychologist determines that someone had a normal childhood, it does not point to a specific home environment but rather a healthy one, which may or may not realistically reflect the majority of home environments. Lastly, when an optometrist says that a person has normal vision she is not appealing to ideal vision, which may be closer to that of a fighter pilot. Behavioral concepts of normality also suffer from subjective meaning and are contextually problematic related to definitions of average, majority, or ideal. Lastly, not always do statistical, social, and biological understandings coincide although advances in science can shorten the gap in some cases. They are three categories of meaning, not three different meanings.
Why different parts of an organism evolve the way it does (Wright) or whether function is to be understood in terms of the organism’s overall ability to survive and reproduce (Boorse) will affect one’s conception of biological normality. When applied to behavior, we may actual redefine the type of behavior under examination, which may affect the social meaning of the term normal. Like Press, Wachbroit refers to medicalization of behavior as problematic within the context of normality because of the conflation of social and biological meanings. He points to education of the public of the distinction so that conflation is minimized. He shows that Fukuyama’s defintion of human nature conflates the distinction. His definition of human nature allows for change over time in case of disease or medical advances but Wachbroit rejects a changing view of what it means to be human. He concludes by asking the question, which is relevant to our research, whether something is human nature if there is 51% or more of a genetic component versus something that is 49% genetic in nature? Does the environmental factors of causation have anything to do with human nature?