In a new twist to the nature-versus-nature debate raging in the academic and popular literature, two professors have published a study suggesting that school conditions can have a substantial impact on students' test scores.

Shattuck Professor of Government Paul E. Peterson and Jay P. Greene, assistant professor of political science at the University of Houston, found that, among minority students of similar socioeconomic backgrounds, those educated at private schools scored higher on standardized tests than did those from public schools.

Peterson said the results of the study, "The Effectiveness of School Choice in Milwaukee," help to refute the claims of Charles A. Murray '65 and the late Richard J. Herrnstein in The Bell Curve that intelligence is determined in part by race.

"Our study shows that minority students can learn given the proper circumstances:...a proper learning environment," Peterson said.

Peterson added that a "primary motivation" in his decision to become involved in the study was his desire to stem the influence of Herrnstein and Murray's book on education policy in the U.S.

Peterson and Green's study was based on the examination of an experimental Milwaukee program, begun in 1990, which brought stu- dents from low-income, inner-city families to private schools through a voucher system.

According to their findings, the students who attended private schools scored an average of three points higher on a standardized reading examination and five points higher on a math test than students from similar socioeconomic backgrounds, after three years of attendance in the private schools.

After four years, the students in the voucher program advanced to an average of five points higher on the reading and 12 points higher on the math than their peers in public schools.

According to Peterson, the data used in the study were singularly reliable for educational research.

Peterson noted that the control group in the public schools was drawn from a pool of students rejected from the voucher program, thus ensuring that these students were from families concerned about education.

Despite the positive results of the study, Peterson does not recommend drastic changes based on its findings, but instead suggests that policies and programs should be created that are consistent with the data drawn from similar experiments.

The sort of program upon which Peterson and Greene's study is based is the subject of fierce debate in states from Ohio to Pennsylvania, according to Peterson.

In these controversies, Peterson said, teachers' unions have opposed the creation of pilot programs that siphon qualified students from public to private schools.

"Teachers' organizations take the position that because of the family background of their students, the public schools can't do any better," Peterson said. "This smacks of the pessimism of the Herrnstein position."

Peterson said he believes teachers' organizations oppose such programs because of their fear "of competition to the public school system as it exists today."

"I think that it is unfortunate that we have vested interests that are trying to stop this sort of research," Peterson said. "We have to keep our eye on children, and what is best for them.