Considerable interest has been focused over the years on estimating the relative importance of genetic and environmental factors on differences in rates of cardiovascular disease in blacks and whites. However, recent advances in molecular science have helped to illuminate the underlying complexity of this problem. Attempts to impute the genetic component from "what was left over" after control for a limited set of environmental exposures is increasingly recognized as naive. The requirements for a model that could account for interactions between genetic and environmental factors far exceeds the precision of our measurements. Although it is obvious that blacks experience not only unique environmental exposures, such as white racism, but more intense exposure to common factors, such as obesity, current methods make it very difficult to summarize these effects. Simpler models, using data from large samples, could provide greater precision and might illuminate the exposure-outcome relationships common to all groups. Meanwhile, efforts to identify genetic underpinnings of complex disorders will have to reach a much higher level of development before useful conclusions can be reached about the magnitude and variation of effects between racial and ethnic groups.