Spicy Ideas From Evolutionary Biology - Dr Jerry Coyne

Coyne argues that the culture of mandatory disclaimers—such as acknowledging historical injustices before discussing male issues—is a form of self-censorship that reinforces the idea that some truths are harmful. He points to the American Association of University Professors' stance that universities should allow disagreement without offense. He believes that by dropping disclaimers and simply being polite, one can still persuade and maintain integrity. He himself has stopped adding notes like 'this comes from a right-wing source but it's true' because it implies truth depends on the source's politics.

Coyne argues that many ideologically motivated denials of biology—such as the claim that sex is a spectrum, that race has no biological basis, or that men and women have no innate differences—stem from a desire to make nature align with progressive values. He calls this the reverse naturalistic fallacy. For example, if someone feels gender fluid, they insist sex must be non-binary; if they believe in infinite human malleability, they deny genetic influences on behavior. This fallacy, he says, is rooted in postmodernism's rejection of objective truth and has infected science, leading to self-censorship and the erosion of empirical standards. He sees it as a major driver of the ideological capture of biology.

Coyne describes how he used to add disclaimers like 'this comes from the Wall Street Journal op-eds but it speaks the truth anyway' when citing sources, or when discussing sex differences he would preface with reassurances that this doesn't invalidate transgender identities. He now sees this as capitulating to the mindset that truth must be sanitized. He argues that the purpose of academia is to allow disagreement without offense, and that being civil while stating facts is sufficient. He encourages others to drop the 'weird rain dance' of disclaimers and just speak the truth.

Coyne suggests that if evolutionary psychology is to be taken seriously, it must make testable predictions. He offers the 'PET theory': when you marry someone who already has a pet, you will treat that pet worse than your own pet, similar to the stepchild effect. He admits this hasn't been tested but believes it's a valid prediction. He has been urging David Buss to write a paper on testable predictions in evolutionary psychology to counter critics who call it unfalsifiable. He was pleased to learn that Buss's student William has a paper in press showing evolutionary hypotheses are testable and falsifiable.

Coyne lists the six misguided statements his paper addresses: (1) there are more than two sexes/sex is a spectrum; (2) race is a human construct without scientific basis; (3) males and females are not biologically different; (4) indigenous science is just as good as modern science; (5) people don't differ in meaningful genetic ways; (6) evolutionary psychology is a worthless field. He argues each is ideologically motivated and contradicted by evidence. The paper aims to show how these ideas have been misrepresented by media and even scientists. He sees this as part of a broader trend of ideology eroding science, fueled by postmodernism and a left-wing guilt complex.

Coyne describes how he and colleagues used Drosophila populations at various stages of speciation—from those that can still interbreed to fully isolated species—and measured genetic divergence. By calibrating the molecular clock, they could plot a curve of reproductive isolation over time. This was the first such curve for any group, and it remains his most cited paper. The clock ticks on absolute time because of neutral mutation rates and population size effects, not generation time. This finding helps understand why humans, separated for only ~60,000 years, are still one species, while chimpanzees and humans, separated for 7–8 million years, are distinct.