Taylor, who had downplayed the significance of race, eventually had to admit there were some proportionally small differences between population groups. And Robin had to acknowledge having vastly overemphasized the amount of DNA differences between races.
But the two fictional teenagers still clashed over the opening question. Robin believed that there are genes for athletic or intellectual abilities, and that they are the best explanation for racial disparities in the National Football League and in the worlds of math and science. Taylor said genes had nothing to do with it.
Again, neither was completely right.
In their typical classes, the teachers said, they highlight traits driven by single genes — the texture of peas, or a disease like cystic fibrosis. It is an effective way to convey both how traits are transmitted from one generation to another, and how alterations in DNA can produce striking consequences.
But such traits are relatively rare. In Dr. Donovan’s curriculum, students are taught that thousands of variations in DNA influence a more common trait like height or IQ. Only a small fraction of the trait differences between individuals in the same ancestry group has been linked to particular genes. Unknown factors and the social and physical environment — including health, nutrition, opportunity and deliberate practice — also influence trait development. And students are given data about how racism has produced profoundly different environments for black and white Americans.
For Robin, the lessons said, grasping the complexity of it all made it impossible to argue that there was a gene, or even a few genes, specifically for athletics or intelligence, or that the cumulative effect of many genes could make a definitive difference.
And yet, on whiteboards, teachers listed comments and questions they anticipated from real students, including one that recurred in various forms.
“Isn’t this just a liberal agenda?”
Dr. Donovan told teachers that the curriculum also counters the viewpoint represented by Taylor — that ability is affected only by “how you’re raised, the opportunities you have, the choices you make and the effort you put in.” Recent studies, they are told, show that genetic variants play some role in shaping differences between individuals of the same population group.