A new Portland State University study suggests that the likelihood of a child being classified with an educational disability depends on the characteristics of their school and how distinctive they are from their peers.

The study, published in the journal Society and Mental Health, found that disability classifications do not occur reliably across schools. The study used annual child- and school-level data from 378,919 children in a large urban school district between 2006 and 2012.

Dara Shifrer, the study's lead author and an assistant professor of sociology in PSU's College of Liberal Arts and Sciences, said disability classifications are inconsistent and subjective.

"Kids may have the same test scores and same social background, but the school they attend determines whether they'll get a disability classification," she said.

Shifrer said the classifications are meant to help children but can also limit their learning opportunities or be stigmatizing.

"Their peers think differently of them, their teachers think differently of them, they think differently of themselves because people interpret these as biological diagnoses," she said. "But what our study shows is that they're based on things that are socially rooted and subjective. ... No one should feel like this is a firm statement on what this child is capable of or what their trajectory should be."

Shifrer and her co-author, Rachel Fish, an assistant professor of special education at New York University, found that students who are distinctive relative to their peers have a greater likelihood of being classified with a disability.

For example, a low-achiever in a higher-achieving school is more likely to be classified as disabled than a low-achiever in a lower-achieving school.

Among children with similar achievement levels, black children in schools with a lower proportion of black classmates are more likely to be classified as disabled than black children in schools with a higher proportion of black classmates. The same is true for English language learners.

Shifrer said this suggests that educators may act on subjective perceptions or even bias rather than objective indicators like test scores, or are less prepared to support the learning struggles of these students when there are fewer like them in the student body.

The study also found that children are more likely to be classified if they attend schools with a higher teacher-to-student ratio or a wealthier student body population. This may be because teachers are able to devote more time and attention to individual students and go through the special education process, or that parents in those schools are more likely to advocate for disability designations that would benefit their children.

Shifrer suggests that classification decisions might occur more reliably if the team included people from different schools across the district rather than the same school.

"When you have teachers and specialists from both high-achieving and low-achieving schools, you get a more balanced perspective of whether this child actually has a disability," she said. "They could also mask the race of the child, but it's important to insert some kind of checks and balances to ensure things are happening consistently as much as possible."

Ultimately, Shifrer said these disability classifications should be recognized within and outside of schools as only representing part of the picture - they should not be perceived to capture all of a child's complexity or allowed to seal a child's destiny.