Thread by @FondOfBeetles

Sexual dimorphism.

Systematic differences between the two sexes of a gonochoristic species of a physical characteristic (or set thereof), not including reproductive anatomy.

Some sexually dimorphic characteristics are non-overlapping (e.g. deer antlers) while some are very overlapping (e.g. human height).

The extent of overlapping observation/measurement is irrelevant. The only requirement is a robustly-detectable difference between sexes.

Many female humans are taller than many male humans, yet the population descriptions of height in humans consistently reveal that males as a sex class are taller than their demographically-matched female peers.

Height in humans is a sexually dimorphic characteristic.

Body shape/size differences are perhaps the most common examples of sexual dimorphism across many species. Male humans as a sex class are taller, with wider shoulders and narrower hips, more muscle mass, and so on.

In some species, females are the big ones 💪

Sexual dimorphism is canonically understood as a result of sexual selection, that is, competition between and within sexes for mates. Some, however, may be a result of simple natural selection acting upon different behaviours between the sexes (e.g. how males and females feed).

Over the last few years, we have seen a concerted effort to deny the material reality of male and female sex classes.

But I admit that I am absolutely banjaxed by the shift from ‘sex is a spectrum’ to ‘humans are not sexually dimorphic’.

‘Sex is a spectrum’ is occasionally used in good faith to further a compassionate understanding of atypical bodies.

More often, it is no more than mindlessly-repeated, ideological trash.

‘Humans are not sexually dimorphic’ is flat-out, indefensible, scientific nonsense.

No longer do we need to infer from ‘sex is a spectrum’ that people are evolution-deniers.

Now they are saying it out loud.

A footnote: Actually, it’s worse than I thought.

Even those who assert ‘sex is a spectrum’ evoke bimodal distributions of various characteristics, relying on the sometimes overlapping ‘middle ground’ measurements to make their claim.

But they describe modes/clusters/whatever. They at least recognise average differences in characteristics.

So I’m not clear that ‘humans are not sexually dimorphic’ is a progression from ‘sex is a spectrum’, unless one has no idea what sexual dimorphism is.

In which case, I’d advise people to consult a textbook or similar.