Even among caregivers of those with disabilities, new research suggests that the sight of someone with facial characteristics typical of Down syndrome triggers negative thoughts.

In a study published this month in the journal PLoS ONE, researchers showed a group of 165 adults standardized images of children with Down syndrome and typically developing kids, all exhibiting neutral expressions.

As the photographs flashed before them on a screen, participants were asked to use keys to respond as quickly as possible to assess both positive and negative character traits, judging for example whether or not a child appeared “affectionate” or “stupid.”

While the adults in the study expressed more positive than negative thoughts about kids with and without Down syndrome, negative opinions became more frequent as a child’s facial features tended more toward those characteristic of Down syndrome.

This trend held true even among the 55 study participants working as professional caregivers for people with intellectual disabilities, though these individuals held the most positive thoughts of all the study participants about kids with Down syndrome.

Researchers from Aix-Marseille University in Marseille, France who were behind the study say that the findings are significant because their test measured implicit thoughts, or feelings that people may not freely divulge.

“Research into the social perception of intellectually disabled persons has been largely one-sided, focusing predominantly on thoughts and feelings, which may be distorted by social desirability concerns. In the current research, we found evidence of subtle forms of prejudice toward children with special needs at both the explicit and implicit levels,” they wrote.

The fact that professional caregivers were more likely to express positive impressions, however, suggests that relationships with individuals who have intellectual disabilities do make an impact, the study authors said.