When evaluating the same black student, white teachers expect significantly less academic success than black teachers, a new study concludes. This is especially true for black boys.

When a black teacher and a white teacher evaluate the same black student, the white teacher is about 30 percent less likely to predict the student will complete a four-year college degree, the study found. White teachers are also 12 percent less likely to expect their black students will graduate high school.

"What we find is that white teachers and black teachers systematically disagree about the exact same student," said co-author Nicholas Papageorge, an economist in the Krieger School of Arts and Sciences at the Johns Hopkins University. "One of them has to be wrong."

The study, forthcoming in the journal Economics of Education Review, and now available online, suggests that the more modest expectations of some teachers could become self-fulfilling prophecies. These low expectations could affect the performance of students, particularly disadvantaged ones who lack access to role models who could counteract a teacher's low expectations, Papageorge said.

"If I'm a teacher and decide that a student isn't any good, I may be communicating that to the student," Papageorge said. "A teacher telling a student they're not smart will weigh heavily on how that student feels about their future and perhaps the effort they put into doing well in school."

The findings also likely apply beyond the education system, the researchers say -- leading to racial biases in the workplace, the service industry and the criminal justice system.

The researchers analyzed data from the Educational Longitudinal Study of 2002, an ongoing study following 8,400 10th grade public school students. That survey asked two different teachers, who each taught a particular student in either math or reading, to predict how far that one student would go in school. With white students, the ratings from both teachers tended to be the same. But with black students, boys in particular, there were big differences -- the white teachers had much lower expectations than black teachers for how far the black students would go in school.

The study found:

White and other non-black teachers were 12 percent more likely than black teachers to predict black students wouldn't finish high school.

Non-black teachers were 12 percent less likely to expect black students to complete a four-year college degree. Expectations dropped further for non-black teachers of a different gender than the student. The drop increased even more for black boys, especially when their math teacher was making the assessment.

Non-black teachers were 5 percent more likely to predict their black boy students wouldn't graduate high school than their black girls.

Black female teachers are significantly more optimistic about the ability of black boys to complete high school than teachers of any other demographic group. They were 20 percent less likely than white teachers to predict their student wouldn't graduate high school, and 30 percent less likely to say that then black male teachers.

White male teachers are 10 to 20 percent more likely to have low expectations for black female students.

Math teachers were significantly more likely to have low expectations for female students.

For black students, particularly black boys, having a non-black teacher in a 10th grade subject made them much less likely to pursue that subject by enrolling in similar classes. This suggests biased expectations by teachers have long-term effects on student outcomes, the researchers said.

Papageorge's co-authors are Seth Gershenson, an assistant professor of public policy at American University, and Stephen B. Holt, a doctoral student at American University.

"While the evidence of systematic racial bias in teachers' expectations uncovered in the current study are certainly troubling and provocative, they also raise a host of related policy-relevant questions that our research team plans to address in the near future," Gershenson said. "For example, we are currently studying the impact of these biased expectations on students' long-run outcomes, such as educational attainment, labor market success and interaction with the criminal justice system."