While it is often assumed that Deoxyribonucleic acid (DNA) ancestry results illuminate one's true racial or ethnic lineage, the consequence of this inference remains largely unknown. This leaves two conflictual hypotheses largely untested: Do DNA ancestry tests increase racial tolerance or, alternatively, racial intolerance? Two multiwave experiments aimed to test these hypotheses using either real or bogus DNA ancestry results in combination with random assignment and a tightly controlled repeated-measurements experimental design. Bayesian and inferential analyses on both general and student populations of majoritygroup members in the United States (i.e., White/European Americans) indicated no support for either hypothesis on measures including multiculturalism, essentialism, and outgroup bias, even when moderating factors such as the degree of unexpected ancestry and genetic knowledge were considered. Despite wide societal optimism as well as concern, receiving DNA ancestry results appears not to impact feelings and attitudes about other racial and ethnic groups. Implications for prospective test-takers and education are discussed.
Public Significance StatementDespite wide scientific consensus that the concept of "race" is not useful for explaining genetic variation, many assume that their DNA ancestry results illuminate their true racial and ethnic lineages. This tendency has led to significant public and scientific concern-and optimism-over the potentially farreaching implications of this inference. Yet, whether DNA ancestry tests actually increase racial tolerance or, alternatively, intolerance has been largely untested. While we suggest that interventions to increase genetic literacy continue and urge that DNA ancestry testing companies exercise caution when presenting their results (e.g., emphasizing just how much DNA is shared between any two humans), our results suggest that neither the considerable concern-nor intense enthusiasm-for these tests' potential to alter thoughts and feelings toward other racial and ethnic groups is warranted.