...They [the left] have conflated the laudable ethical claim that all humans deserve dignity, respect, and equal moral consideration with the implausible empirical claim that humans are born with roughly the same characteristics and capabilities. This conflation has led to fear, antipathy, and even censorship of writings that examine human variation on socially valued traits because it has encouraged the erroneous idea that human variation is a threat to moral equality.
The far-Left, of course, has long been attracted to a view of humans as malleable and almost biologically interchangeable. And it has long argued that the contrary view—that humans are biologically limited creatures who vary widely in potential—is primarily an ideological weapon used to defend the status quo by arguing that inequality is natural and inevitable. Therefore, the moral misunderstandings and confusions that arise from the conflation of “created equal” with “created the same” are not new. Indeed, they have a long history and have inspired furious denunciations of sociobiology, evolutionary psychology, and behavioral genetics (as well as thoughtful and ethically insightful responses).
...It is therefore worth repeating that created equal does not mean created the same on all socially valued traits. For science will continue to reveal genetically caused differences among individuals, groups, and sexes. And if confusion between the moral and the empirical persists, we will find ourselves asked to choose between the truth and our ethical preferences. The good news in this otherwise gloomy scenario is that no such choice is required. Moral equality is not premised on physical or psychological sameness; it is premised on a commitment to human dignity....