Making Sense of Embodiment Part Two - Matter and Body
What exactly is said when it is said that people can be biologically divided into male and female?
Many statements in which this assertion is made can be understood as "The empirical natural science of human biology has established that there are different characteristics in human beings. The empirical natural science of human biology has established that there are different characteristics that are male or female and which make it so that the people who possess them are male or female."
These properties are then located, for example, in the reproductive organs, the hormonal balance, the germ cells or the chromosome set: a penis, a body that produces testosterone, or has small gametes, or an XY-chromosome set is "male", and correspondingly a uterus, a body that produces estrogen, or has large gametes, or an XX-chromosome set, is "female".1 The division into males and females is therefore empirically based, although this is compatible with the fact that there are people who have male and female characteristics - not everything always runs smoothly in nature.
However, the very fact that things do not always run smoothly in nature now allows us to ask which characteristics can plausibly be identified as the site of biological sex. If one characteristic (e.g. hormone balance) is within the normal range, while another (perhaps the chromosome set) is not, which one should be the decisive factor? This question cannot be decided on the basis of empirical observations, because it is precisely their validity with regard to a certain judgement that is at issue.
The biological sex cannot be determined by a single characteristic. There is much to suggest that we are dealing with a homoeostatic property clustering.2 What does that mean?
The concept of a homoeostatic property cluster(ing) (henceforth: HPC) appears in the writing of Richard Boyd, a philosopher of science. He writes:
“There are natural kinds, properties, etc. whose natural definitions involve a kind of property cluster together with an associated indeterminacy in extension.”3
So, the idea is that for some definitions, there is a clustering of properties which constitute them, and since they are constituted by clusters of properties, the entirety of objects which fall under the definition is not fixed. The following is true of an HPC:
There is a family F of properties which are 'contingently clustered' in nature in the sense that they co-occur in an important number of cases.
Their co-occurrence is not, at least typically, a statistical artifact, but rather the result of what may be metaphorically (sometimes literally) described as a sort of homeostasis. Either the presence of some of the properties in F tends (under appropriate conditions) to favor the presence of the others, or there are underlying mechanisms or processes which tend to maintain the presence of the properties in F, or both.
The homeostatic clustering of the properties in F is causally important: there are (theoretically or practically) important effects which are produced by a conjoint occurrence of (many of) the properties in F together with (some or all of) the underlying mechanisms in question.
There is a kind term t which is applied to things in which the homeostatic clustering of most of the properties in F occurs.
This t has no analytic definition; rather all or part of the homeostatic cluster F together with some or all of the mechanisms which underlie it provides the natural definition of t. The question of just which properties and mechanisms belong in the definition of t is an a posteriori question - often a difficult theoretical one.
Imperfect homeostasis is nomologically possible or actual: some thing may display some but not all of the properties in F; some but not all of the relevant underlying homeostatic mechanisms may be present.
In such cases, the relative importance oft he various properties in F and of the various mechanisms in determining whether the thing falls under t - if it can be determined at all - is a theoretical rather than an conceptual issue.
In cases in which such a determination is possible, the outcome will typically depend upon quite particular facts about the actual operation of the relevant homeostatic mechanisms, about the relevant background conditions and about the causal efficacy of the partial cluster of properties from F. For this reason the outcome, if any, will typically be different in different possible worlds, even when the partial property cluster is the same and even when it is unproblematical that the kind referred to by t in the actual world exists.
Moreover, there will be many cases of extensional vagueness which are such that they are not resolvable, even given all the relevant facts and all the true theories. There will be things which display some but not all of the properties in F (and/or in which some but not all of the relevant homeostatic mechanisms operate) such that no rational considerations dictate whether or not they are to be classed under t, assuming that a dichotomous choice is to be made.
The causal importance of the homeostatic property cluster F together with the relevant underlying homeostatic mechanisms is such that the kind or property denoted by this a natural kind in the sense discussed earlier.
No refinement of usage which replaces t by a significantly less extensionally vague term will preserve the naturalness of the kind referred to. Any such refinement would either require that we treat as important distinctions which are irrelevant to causal explanation or to induction or that we ignore similarities which are important in just these ways.4
Now, this is a lot, and it sounds quite complicated, but the takeaway is pretty simple. Take properties that are typically taken as the determinants of biological sex: chromosomes, hormones, gametes, primary sexual organs, secondary sexual organs. These properties have a certain tendency to occur together in a body - to cluster, in Boyd’s terms. A body that has XX-chromosomes will often produce gametes of a specific type, will have a specific hormonal balance, a specific anatomy, and so on. The same is true of a body with XY-chromosomes. Furthermore, the clustering of these properties tends to establish a certain homoeostasis, so that the occurrence of some properties makes it more likely for others to occur as well. And the occurrence of these clusters is what makes a body (biologically) female or male (whatever that means).
However, it is possible for a body to lack specific properties from a cluster or to even have some properties from the other cluster without falling out of the range of objects that are referred to with the term reserved for objects in which the properties cluster. So, a body can have a specific hormonal balance without having the secondary sexual characteristics (for whatever reason). This, of course, means that biological sex is everything but immutable. Remember that, according to Boyd, the subsumtion of fringe cases under a label that is used to attribute the homoeostatic clustering of a set of properties is not a conceptual question but an empirical. This means, that it has to be decided on a case-by-case basis which biological sex a certain body has if the homoeostasis is imperfect. Now, gender-affirming care for trans people can be understood as the artificial “shift” of some of the relevant properties, so that the body in question gravitates towards a totally different HPC. Granted, the chromosomes remain all the same, but this seems hardly relevant once all the other properties of the cluster have changed.
If, however, biological sex cannot be determined by a single property, but requires several mutually dependent properties, of which not all need to be present, and it is an open question which and how many must be present for the attribution of a biological sex to be justified, then there is reason to believe that "biologically male" and "biologically female" are not empirical concepts. What is empirically observed are not two different biological sexes, but rather the occurrence of characteristics that can be assigned to one of two groups. The distribution of these two HPCs is then interpreted as sexual dimorphism, and the respective bodies are interpreted as male or female (or, in some cases, neither).
In an earlier post, I already argued that this line of thought amounts to a mereological fallacy.
I’m grateful to Hane Htut Maung who let me read the draft of a paper in which he makes this case.
Boyd, Richard N.: "How to be a moral realist” in: Geoffrey Sayre-McCord: Essays on Moral Realism pp. 181-229.
Boyd, op. cit.