According to Nadia Abu El-Haj, some biomedical researchers in the United States use racial groups as surrogates for individuals who consider themselves to be members of such groups. Why?

Answer: Because In recent years the cost of sequencing individual genomes has been dropping, with the $1000 genome on the horizon we will soon have the ultimate tool for individualized medicine. However the cost has been high enough that many researchers have used genetic data from other members of populations to which individuals become as a surrogate for an individual's particular genome.