It is common knowledge that scientists are those persons who have the unique attributes required to perform in the role, but contrary to what is widely believed, scientists might also be those who have had access to resources of which other members of the population have been deprived. This study investigates the effectiveness of interventions designed to mediate the negative influence of ascription (race and ethnicity) on the scientific talent pool (students having interest and ability in science). Minorities refers to participants representing the major ethnic and racial groups in the New York City school system: Blacks and Hispanics. Cross-tabulations showed that urban underachieving public high school students take significantly more mathematics and science classes, more frequently graduate from high school and more often enroll in college as compared with students of the same population, who were not exposed to the program. These findings on the effectiveness of tutoring, career counseling, exposure to industrial and academic research sites and to scientist role models, and after-school and weekend classes in mathematics and science, reinforce the observations of Thomas (1986) of the importance of prerequisites for increasing participation of minorities in the natural and technical sciences and mathematics. They extend knowledge of factors which lessen the effects of ascription on educational attainment, and which promote meritocratic conditions for achieving a scientific occupation.