Until recently, virtually all medical research was conducted on upper-middle class White men. This left health care professionals, as well as many other segments of the population, without sufficient information to deliver adequate health care to both genders and to the diverse groups of ethnic minorities in the United States. Fortunately, research policy has changed and intense efforts are now being made to collect data not only from men but also from women and majot ethnic U.S. minorities. The resultant data, however, create a dilemma concerning how we evaluate data that show differences between ethnic groups. All human beings are similar in most ways--i.e., sharing basic anatomy, physicology, and biochemistry--although there are some obvious racial distinctions such as skin color. Historically, there has been reluctance on the part of the scientific community to accept data indicating that ethnic groups may differ in certain health characteristics, especially if the data show an ethnic group to be less healthy in some respect. This sensitivity is greatest in ethnic groups who have been subjected to perjorative statements and stereotypes about their health and physical ability in the past. On the other hand, we must evaluate comparative ethnic data because they may provide information that can truly lead to better care for individual communities.