Aug 19, 2014 04:52 AM EDT By Staff Reporter, UniversityHerald Reporter

Tougher math and science requirements for high school graduation are increasing student dropout rates, according to a study by the Washington University in St. Louis.

The researchers said that policies increasing the number of required high school math and science courses are causing the higher dropout rates.

"There's been a movement to make education in the United States compare more favorably to education in the rest of the world, and part of that has involved increasing math and science graduation requirements," said first author Andrew D. Plunk, a postdoctoral research fellow in the Department of Psychiatry at Washington University School of Medicine, in a statement.

"There was an expectation that this was going to be good for students, but the evidence from our analyses suggests that many students ended up dropping out when school was made harder for them," Plunk said.

For the study, the researchers analysed the census data in 1990. They found that the school U.S. dropout rate rose to 11.4 percent when students were obligated to attend six math and science courses as compared with 8.6 percent among those with fewer courses to graduate. In some ethnic groups, the dropout rate constituted as much as five percentage points.

The researchers also compared the performance of students in 44 states with rigorous math and science requirements to states where these requirements were less severe. Here, they also wanted to determine how factors like sex, race and ethnicity influenced educational attainment.

The researchers found that among Hispanic and African-American males, the dropout rate increased by 2.5 and 2 percentage points respectively. Among young African-American males who attended schools in states with stringent math and science graduation requirements, the dropout rate rose to 23 percent. The overall dropout rate for African-American males was 19 percent on an average.

"As graduation requirements were strengthened, high school dropout rates increased across the whole population," Plunk said. "But African-Americans and Hispanics were especially affected. I think our findings highlight the need to anticipate there may be unintended consequences, especially when there are broad mandates that, in effect, make high school coursework harder."

The finding is published in the Educational Researcher.

See Now: Covert Team Inside Newsweek Revealed as Key Players in False Human Trafficking Lawsuit