Experiences don’t shape our personalities, our bodies do

The argument

Evidence supporting FPC is growing – not only in terms of how one's looks influence our personality traits, but even our approaches to finding romantic partners and our political beliefs. The claim being made is about the direction of causation: the body a person has is treated as shaping the disposition they develop, rather than the disposition being laid down by what happened to them early on. For instance, take trait extroversion, which involves not only being more sociable, but also more adventurous and willing to take risks. In evolution, it would make strategic sense if stronger, more physically capable people exploited their bodily advantages by being more extroverted. The reasoning is that a trait's usefulness depends on the body carrying it. Assertiveness and risk-taking pay off for someone equipped to prevail in a confrontation and cost more for someone who is not, so a disposition calibrated to physical capability would be selected for over one adopted regardless of it. That's exactly what some research has found. One study from Germany's University of Göttingen recently reported that of more than 200 men, those who were physically stronger tended to be more extroverted, especially in the sense of being more assertive and physically active. The same strength-extroversion association was not found among the women in the study — a difference that matters to the interpretation, since a purely cultural account of why strong people act confidently would be expected to apply to both. While experiences, especially in childhood, can affect our personality, what determines it is our body shape when growing into adulthood. On this argument childhood experience modulates something it does not set, and the settling factor is the body a person grows into.

Premises

Counter-arguments

On the other hand, our body shape (or genetic make up) can shape our personality. Human’s experiences of how they are treated, based on their body type, can produce positive and negative traits in personality.

Rejecting the premises

[Rejecting P1] "FPC" is introduced without explanation and the claim that evidence for it is growing is unsourced. Extending it to romantic behaviour and political belief compounds the problem, since no study is cited for either. [Rejecting P2] This is an evolutionary just-so story — a plausible rationale constructed after the fact, which could as easily be told in reverse, with physically weaker people benefiting from greater sociability in order to secure allies. Reasoning of this kind constrains nothing and predicts nothing. [Rejecting P3] A single study of roughly 200 men reporting a correlation between strength and assertiveness cannot bear this weight, and the argument itself reports that the association did not hold for the women in the same sample — which counts against the evolutionary account rather than for it. Correlation also leaves the direction open: as the counter-argument notes, how people are treated on account of their build is itself an experience, so the finding is compatible with the position it is meant to refute. The body then concedes the case outright in granting that experience "can affect our personality".