A new study conducted by researchers at the Yale University Child Study Center claims to have uncovered racial bias in teachers towards black preschoolers in America.

The study asked more than 130 preschool teachers to watch video clips of children in classrooms, looking out for “challenging behavior” as they did so.

The children in the videos were actors, and the clips actually showed no challenging behavior, the Washington Post reports. The study conducted reports that the teachers did not know that the children were actors.

One revealing behavioral habit displayed by the teachers who were viewing the videos, however, was in fact observed and noted down throughout the experiment — that as the teachers scanned the video clips looking for bad behavior, they spent more time looking at black children than white children.

Lead researcher and Yale child psychology professor Walter S. Gilliam points out that the findings are a sign that teachers expect problematic behavior from black children, and especially from black boys.

The findings show how deeply rooted racial biases are, Gilliam said, and how badly teachers need training to alter knee-jerk perceptions and judgments they make of their students, often without even realizing they are doing so.

Gilliam related the findings to the recent multiple fatal shootings of black men by police and the Black Lives Matter movement by saying:

“Implicit biases do not begin with black men and police. They begin with black preschoolers and their teachers, if not earlier. Implicit bias is like the wind: You can’t see it, but you can sure see its effects.”

The Washington Post’s Emma Brown reports that though black children accounted for 19 per cent of all preschool students in 2013-2014, they made up 47 per cent of children who received suspensions, according to federal civil rights data.

Gilliam spoke further on the topic of implicit biases saying that even the most well meaning teacher can harbor deep-seated biases unbeknownst to them:

“We all have them. Implicit biases are a natural process by which we take information, and we judge people on the basis of generalizations regarding that information. We all do it.”

However, the findings, though focused on implicit bias, are very much connected to the far-reaching problem of racial prejudice and profiling, a problem that has been highlighted by unrest in the US and the Black Lives Matter movement this year. As reported by the Huffington Post, government official and early childhood expert Linda K. Smith has said that the study’s findings are “far too important for us to ignore.”

After the study, the real purpose of the experiment was revealed to the teachers taking part, after which only one of the 135 teachers involved asked to withdraw their data. Smith said this is a sign that early childhood educators are committed to the uncomfortable task of facing their own biases. She feels that more needs to be done in early education to combat racial bias:

“It’s something probably we all didn’t want to hear, but we needed to know.”

The study, which calls for more rigorous teacher training aimed at tackling racial bias, was funded by the W.K. Kellogg Foundation.