Anorexia Nervosa: Biological vs Social Causes

Read the prompt's second sentence carefully, because it does something unusual: it tells you what it thinks the answer is. Having listed genetic predisposition, serotonin regulation and physiologic weight set points, it adds that given the prevalence of the disorder it seems unlikely that biological causes alone could account for it. That is a position, not a neutral setup, and you have two honest responses. You can accept it and spend the post explaining precisely why biology is insufficient rather than merely agreeing. Or you can push back, which is legitimate if you can support it. What you cannot do is restate the prompt's own claim as though it were your conclusion, which is what a large share of submissions will do. Notice too that the prompt says biological causes alone, which is a narrower claim than the one most posts end up arguing against.

The word doing the work in that sentence is prevalence, so examine the argument rather than accepting it. The reasoning appears to be that a condition whose incidence has varied across time and differs sharply between cultures and cohorts cannot be explained by genetics alone, since gene frequencies do not change on that timescale. That is a sound argument and it is worth stating explicitly, because it is a real piece of reasoning rather than an intuition. But be careful with the inference. Variation in prevalence rules out a purely genetic account; it does not diminish the strength of the biological contribution in any individual case, which is a separate question and one where heritability estimates are substantial. Keeping those two levels apart — the population and the person — is the single most common failure in arguments of this shape, and it is easy to avoid once named.

The framework that resolves this properly is diathesis-stress, and naming it will organise the whole post. Biological factors on this account are not competitors to sociological ones but predispositions that require environmental input to become disorder. Genetic vulnerability, serotonergic function, and set-point regulation establish who is at risk and shape the form the illness takes once established; cultural pressures around thinness, family dynamics, and individual factors such as perfectionism and control determine who among the vulnerable becomes ill. Framed that way, asking which is stronger is asking a poorly formed question, and saying so — while still answering it — is the sophisticated move available here. Answer it anyway, because refusing to answer reads as evasion; the difference is that your answer arrives with a framework attached rather than as a preference.

The prompt then asks you to consider the types of anorexia nervosa in your argument, which is a specific instruction and easy to skip. The restricting type and the binge-eating and purging type differ in more than behaviour: they show different associations with impulsivity, with comorbid conditions, and with course and outcome. That matters for the causal argument, because a factor weighting differently across the two subtypes is evidence that the disorder is not a single causal entity. Using the subtypes to test your own claim, rather than describing them, is what the instruction is asking for and it is the part of the prompt most often reduced to a sentence. If one subtype fits your causal account better than the other, say so — an argument that explains why it applies unevenly is stronger than one claiming to cover everything.

The treatment instruction is a second test of your argument, and it can genuinely discriminate between positions. If biology were the dominant cause, pharmacological treatment should be effective, and the evidence for medication in anorexia nervosa is notably weaker than for several other psychiatric conditions, while family-based and psychological therapies carry the strongest support in adolescents. That asymmetry is evidence for your thesis rather than an aside. Note the complication too: severe starvation produces cognitive and emotional effects of its own, so some of what looks like psychological cause may be biological consequence — nutritional restoration is a precondition for psychological work rather than an alternative to it. That ordering is itself an argument about causation, since a treatment sequence that has to begin with the body tells you something about where the illness is sustained.

Finally, handle the subject with care and source it well. Anorexia nervosa has one of the highest mortality rates of any psychiatric disorder, so avoid framings that imply choice or vanity; the causal argument you are making is in fact the strongest available correction to that misconception. Use the library rather than general websites, since this topic attracts a great deal of unreliable material, and be careful with the causal language in what you read: much of the evidence is correlational, and a difference in serotonergic function observed in patients may be a consequence of starvation rather than a cause of the illness. Noticing that ambiguity in your own sources is exactly the reasoning this discussion is designed to develop. Flagging one such source explicitly, and saying what would be needed to settle the direction, is worth more than a longer list of findings taken at face value.