Article summary of The removal of Pluto from the class of planets and homosexuality from the class of psychiatric disorders: a comparison by Zachar & Kendler - Chapter

What is the history of decisions regarding Pluto?

This article compares the removal of Pluto as a planet to the removal of homosexuality from the DSM list of mental disorders. The article argues that competition between groups for ‘scientific authority’ is normal when it comes to scientific progress. In both types of removals, it was the complex relationship between empirical evidence and abstract concepts that led to problems in classification.

The existence and location of Pluto was predicated based on wrong calculations. The decision of classifying homosexuality as a psychiatric disorder, was based on the assumptions of the degeneration theory, which first was a theological concept but, with the introduction of evolutionary theories, became a psychological theory. Sexual practices were seen as signs of progressive psychic decline. This caused the inclusion of homosexuality in the DSM-I.

One of the most important questions of this article is: who decides on a controversy if the scientific community cannot agree on it? It is suggested that disagreement, and thus postponing a decision, could be useful in this case. If it's absolutely necessary to make a decision immediately, there are two important things to remember: 1) the decision should be made by well-informed experts, and 2) the members of the broader scientific community must believe that the decision is fair.

What were the scientific decisions concerning Pluto and homosexuality?

The controversy about Pluto peaked when the planet Eris was discovered. It was larger than Pluto and had a moon, and thus appeared to be a 10th planet. The Working Group forced a vote on the Pluto issue; seven people voted in favor, seven voted against and seven voted in favor of the idea that there should be several subsets of planets.

Regarding homosexuality, this was long considered as an immoral and illegal perversion. In 1973, the American Psychiatric Association (APA) voted homosexuality out of the DSM. This decision was preceded by numerous protests at the annual APA conventions. The protestors revealed cases of discrimination of homosexuals, that were justified by the claim that homosexuality was a mental disorder. Additionally, several scientific discoveries influenced the decision:

• Afred Kinsey et al. showed that there were high prevalence rates for homosexual activity.
• Evelyn Hooker's concluded that homosexual relationships are usually long-term and committed, instead of impulsive.
• Robert Spitzer attended meetings of gay psychiatrists and concluded that they were underdogs who were in pain. He wanted to help them. He concluded that homosexuality differed from psychiatric disorders, because they don't lead to impairments in social functioning.

Both the decision of removing Pluto and the decision of removing homosexuality caused some protest among scientists. And in both cases, the parties felt considerable pressure to reach a decision. The decision was made by redefining the concepts of planet and psychiatric disorder (e.g. it causes distress and dysfunction).

What do scientists believe?

Hull and Longino believe that the social nature of science, which involves different research communities assessing each other’s work, is required if scientific authority is to be objective. However, one of the difficulties of this is that scientific authority is an abstract concept, and it is hard to decide who holds this scientific authority.

Therefore, one of the main criticisms was not the process of voting, but the belief that authority had been provided to the wrong communities. In these cases, the dynamicists were given authority over the geophysicists and the research academics over the practicing psychoanalysts.

Scientific communities normally rely on various epistemic communities with different research problems, methodologies, and information. However, when authority is allocated to a single classification, it inevitably blocks the normal dispersion of epistemic authority in the respective sub-communities.

To avoid being a popularity contest, it is evident that informed experts should make decisions regarding the respective scientific community, but how are these experts chosen? In both research areas, people agree that experts should have knowledge and experience, but they did not agree about what kind of experience and knowledge. In broad fields like astronomy and psychiatry, there are several different expert groups and each have their diverse interests and incentives, which will most likely influence their decisions.

What can be concluded?

The goal of this article is not to criticize or dismiss the presence of partisanship and politics in academic classification, but to demonstrate that science is and will always be carried out by fallible human beings. Conflicts and controversy are part of scientific development. The difficulties that can exist in any scientific discipline are due to the fact that they often rely on abstract conceptualizations, that there are often social, psychological and economic implications with each classification, and that the existing classifications are approximations as they do not account for all of the existing empirical data on the topic at hand.

There are several ways to deal with these problems. When delegating authority, academic fields need to aim to choose experts in a way that is fair and consistent. These groups have to be self-critical and should include both conflicting and different perspectives. Agreement will not necessarily be reached just because the integrity of the process is met, but it is a necessary requirement for the scientific community and its continued authority.