Discussing human diseases is a common way to engage middle and high school students in genetics. But a series of experiments suggests how teachers approach the discussion could either break down or reinforce students’ racial biases.
Many middle and high school biology units highlight inheritable diseases such as cystic fibrosis, Tay-Sachs, and sickle-cell anemia—which disproportionately affect those of European, Ashkanazi Jewish, and African descent, respectively—as case studies of genetic influences. Students can trace these diseases using the traditional Mendelian punnet square, making them easier to analyze than say, breast cancer, which can also be inherited but which involves significantly more genes and environmental influences.
But that simplicity has a downside.
In a series of studies, researchers led by Brian Donovan of BSCS Science Learning found that it leads students to overestimate how much human beings actually differ genetically Students whose biology classes associated specific diseases with race were significantly more likely to consider people of different races to be more genetically different, and to use genetics to explain differences in academic achievement between students of different races. Any two people share all but .1 percent of their DNA—and of that one-tenth of a percent, only 4.3 percent of the differences are related to heritage groups commonly associated with “races,” such as those from Africa, Asia, or Europe. But Donovan and his colleagues found students thought between 27 percent and 40 percent of human variation was related to race. Students who participated in the more simplistic discussions of race and human disease were significantly more likely than those who did not participate to believe academic achievement gaps were caused by genetic disparities.
Phillip Keck, a science teacher at the Live Oak School in San Francisco who took part in the study, discovered that firsthand in one of his 7th grade science classes.
“I just presented a flat statement like, ‘Humans of African descent are more likely to have sickle-cell disease.’ It may sound like an objective and flat statement, but students were kind of taking that idea and running with it,” he recalled. One student, for example, “concluded that people were probably more likely to get that disease because they were a different kind of person. ... Black people are a different type of animal than white people, which are a different type of animal than Asian people,” Keck recalled. “The connection he made was that there were diseases his pet dog could get but he couldn’t get, and so it’s probably the same thing with people.”
“Even if you improve the quality of the science curriculum itself, that doesn’t necessarily mean that you’re addressing this additional issue of [racism] that can be present,” Keck said.
Reducing Racial Bias
So should science teachers avoid talking about genetics and human disease? No, Donovan said, but they should make sure students understand the more complex picture of how many genes and environmental factors affect most human traits and diseases.
Donovan and his colleagues found that teaching middle and high school students accurate, more nuanced information about genetic similarities and differences among people and multifactorial genetics in disease significantly improved students’ science understanding, and also significantly reduced their racial biases. Those findings were reported online last week in the Journal of Science Education. (The Next-Generation Science Standards, which are used in 19 states and the District of Columbia, call for students to learn multifactorIal genetics as part of its high school standards on heredity, but does not require that it be taught in middle school.)
Separate tests of the curriculum, developed by among students in grades 8-9 and 9-12 in Colorado, California, Massachusetts, and the District of Columbia, found it was equally helpful for both younger and older students, but researchers found students’ racial bias was only reduced when they understood a more complex picture of genetics.
“I think kids need to learn a little bit of [Mendelian genetics]. They need to have a model, a really simple model of how genes work. But I think the story can’t end with Mendel,” said Donovan, who is continuing to study the curriculum with Donovan with the group BSCS Science Learning. “This story needs to end with a multifactorial model of inheritance where you have many genes having a proportionally small effect on a complex human trait and where the environment can have a proportionally large effect on a human trait.”
Participating in the study has “completely changed the way I do absolutely everything I teach,” Keck said. “The issue that it raised for me is that anything that you communicate to the kids can have massive and significant unintended consequences. If I communicate an idea about the structure of DNA and I do it carelessly, they might develop an incorrect idea about the structure of DNA. And you don’t want that, but ... it’s probably not going to directly lead to them treating someone differently. But specifically on this topic, teaching the kids misleading information about this topic does have a direct impact on the way that they treat one another,” he said.
And science teachers will likely need more training and support to raise issues of genetics and race in middle and high school classrooms, he said.
“A question about the periodic table is not a super-loaded thing, but if a kid asks questions about this topic, it’s very challenging,” Keck said. “I don’t think there is an easy way to get better at it except to realize that science teachers are already involved in this, whether we like it or not. So if you’re teaching genetics, you are teaching about these ideas and you can accept that reality and start to work on it and try to improve upon it or not.”
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