Objectivist definitions of dysfunction do not solve the problem
Dysfunction can be defined at the level of the phenomenon or in terms of underlying causal mechanisms. When dysfunction is defined at the level of the phenomenon, a typical strategy is to show a disadvantageous deviation from the norm, ie, the phenomenon is statistically atypical in a harmful way. Dysfunction at the level of the phenomenon requires a quantitative or qualitative comparison with a reference class. This line of reasoning has been developed in its most elaborate form by Christopher Boorse, PhD, in his Biostatistical Theory (BST).4 Boorse’s account is not merely statistical but biostatistical: disease can be said to be present when organs dysfunction to an extent that they statistically deviate from some biological norm.
One of the major problems with this approach lies in defining an appropriate reference class, and usually the question of dysfunction depends on the selection of appropriate reference class. Boorse stated that there are three reference classes based on age, sex, and race. However, this leaves out sexual orientation, potentially making homosexuality statistically atypical. The question then becomes whether sexual orientation should be a reference class or not. Boorse maintained that it should not be and, following his reasoning, had to admit that homosexuality was a disorder (and worked his way around it by saying that it was a disorder but not an “illness”).
In words of Kingma5:
Since the judgement that homosexuality is a disease precedes the judgement that the BST is a correct account of health, it is circular to insist, as Boorse does, that the BST can tell us whether homosexuality is a disease. The BST does not give a real answer, let alone a non-evaluative answer, to such a question. Instead it presupposes the answer it gives.
It is obvious that there is no objective way of determining the appropriate reference class. Should the reference class of posttraumatic symptoms be all individuals of same age, sex, and race, or all individuals of same age, sex, and race who have been exposed to trauma? If the former is true, symptoms of acute stress are statistically atypical, but they are statistically typical if the latter is true.
Defining in terms of underlying causal mechanisms requires a notion of design from which the causal mechanisms deviate. The most precise definition of this approach comes from Wakefield’s Harmful Dysfunction analysis, which states that dysfunction is “a failure of some internal mechanism to perform a function for which it was biologically designed (i.e., naturally selected).”6 Biological and psychological systems are designed by evolution to perform a function within a certain range. Dysfunction is the failure to live up to that design.
The biggest problem is that the biological mechanisms underlying much of psychological functioning are known with only limited detail, and the presence of dysfunction cannot be established definitively. In practice, this leads to the use of surface phenomena as dysfunction indicators, the presence of which infers the existence of dysfunction. First and Wakefield have reviewed strategies employed by the DSM diagnostic criteria to infer the presence of dysfunction. Strategies include the following [emphasis added]7:
[R]equiring a minimum duration and persistence; requiring that the frequency or intensity of a symptom exceed that seen in normal people; requiring disproportionality of symptoms, given the context; requiring pervasiveness of symptom expression across contexts; adding specific exclusions for contextual scenarios in which symptoms are best understood as normal reactions; combining symptoms to increase cumulative pathosuggestiveness; and requiring enough symptoms from an overall syndrome to meet a minimum threshold of pathosuggestiveness.
The use of dysfunction indicators utilizes comparisons with a so-called normal control group, and the use of this normative comparisons makes it highly susceptible to social biases, depending on the societal notions of normal. If a society considers heterosexuality to be the norm, then these strategies would offer little to no protection against pathologizing of homosexuality. This is similar to the problem of reference class that BST faces. Additionally, the inference of dysfunction in the presence of dysfunction indicators is just that—an inference. It is tentative, and its validity remains to be demonstrated.
There are many ways for things to go wrong in biological systems. Mathewson and Griffiths outline four ways things can go wrong from a biological perspective8:
1. Mechanism failure
2. Abnormal environment
3. Normal but inhospitable environment
4. Heuristic failure
As Schwartz points out in his commentary on the Mathewson and Griffiths paper, only the first of these ways of going wrong—mechanism failure—can be considered dysfunction.9 Other ways of going wrong do not come under the category of dysfunction. This is when we are just considering traditional biological systems; once we add psychological and social phenomena into the mix, there are additional ways for things to go wrong. In something as complicated as behavioral disturbances, it can be behaviorally clear that something has gone wrong, yet it may not be entirely clear whether it reflects a mechanism failure or failure of some other sort. All the dysfunction indicators that First and Wakefield describe simply reinforce that something has gone wrong, but do not necessarily distinguish between mechanism failure and other failures that would not qualify as dysfunctions.
1. Rounsaville BJ, Alarcón RD, Andrews G, et al. Basic nomenclature issues for DSM-V. In: A Research Agenda for DSM-V. Arlington, VA, US: American Psychiatric Association; 2002:1-29.
2. Spitzer R. The diagnostic status of homosexuality in DSM-III: a reformulation of the issues. Am J Psychiatry. 1981;138:210-215.
3. Bolton D. What is Mental Disorder?: An Essay in Philosophy, Science, and Values. Oxford, United Kingdom: Oxford University Press; 2008.
4. Boorse C. Health as a theoretical concept. Philosophy of Science. 1977;44:542-573.
5. Kingma E. What is it to be healthy? Analysis. 2007;67:128-133.
6. Wakefield JC. The concept of mental disorder: diagnostic implications of the harmful dysfunction analysis. World Psychiatry. 2007;6:149-156.
7. First MB, Wakefield JC. Diagnostic criteria as dysfunction indicators: bridging the chasm between the definition of mental disorder and diagnostic criteria for specific disorders. Can J Psychiatry. 2013;58:663-669.
8. Matthewson J, Griffiths PE. Biological criteria of disease: four ways of going wrong. J Med Philos. 2017;42:447-466.
9. Schwartz PH. Progress in defining disease: improved approaches and increased impact. J Med Philos. 2017;42:485-502.