Indirect genetic effects
Scientists are able to study indirect genetic effects on a child, even if those effects come from the child's parents. This can be difficult because the parents also pass down genes to the child. Scientists only look at genes that are not passed down. If they did not do this, they might be measuring the direct effect of the gene. They do this by getting information on many of the genes in the mother, father, and child, to see which ones are passed down. To study indirect genetic effects, scientists only look at the genes that were not passed down.