(CNN) Implicit bias is an uncomfortable subject for many people, especially those who believe they don't have any racial bias. But we all have it. We're just not always aware of it and how deeply rooted it can be.

It's certainly an issue we've been grappling with as a country for the past few years as part of a national conversation about race and policing after dozens of shootings of black men by white police officers.

Now comes a study, presented to federal and state educators in Washington, D.C., on Wednesday, showing how bias can have a devastating impact as early as the preschool years.

Black children in preschool are more than three times likely to be suspended than white children, according to data (PDF) from the US Department of Education's 2013-2014 Civil Rights Data Collection. Based on the findings of this new study (PDF) from the Yale Child Study Center, one of the reasons for that racial disparity may be implicit bias on the part of preschool teachers.

More than 130 current and student preschool teachers and administrators took part in the study, which lead researcher Walter Gilliam , director of the Edward Zigler Center in Child Development and Social Policy at Yale University, believes is the first of its kind. The participants were told the goal of the study was trying to learn how teachers detect challenging behavior in the classroom. They were shown a series of video clips and told that some of the clips may or may not contain challenging behavior.

All of the students in the videos were actors, and none of the clips contained any challenging behavior, but the preschool teachers and staff did not know this.

With the use of eye-tracking technology, researchers found that preschool teachers and staff spent more time watching boys and black children, compared with girls and white children. When the educators were asked specifically which of the children required most of their attention, 42% of the teachers said black boys did. Thirty-four percent said white boys required most of their attention, followed by 13% for white girls and 10% for black girls.

What appears to be happening, said Gilliam, is that teachers are expecting more challenging behaviors from the black children, especially the black boys, and therefore may track them more in the classroom than they do other children.

"So they watch them a whole lot more closely when they think they are going to misbehave, and if that's where you're looking, that's probably where you're going to find" the challenging behavior, said Gilliam, who is also associate professor of child psychiatry and psychology for the Yale Child Study Center. "That might actually lead them to finding more than they would find with other children because they're inclined to expect it with these children, and that's where they're paying attention."

Mirroring research on empathy

In a separate exercise, the preschool teachers and educators were presented with a vignette about a 4-year-old preschool student with behavioral challenges. Some were told the child's name was Emily or Jake, stereotypical white names, while others were told the child's name was Latoya or DeShawn, stereotypical black names. The teachers and staff were also told biographical information about the child such as how his or her home life is turbulent, how the child's mother struggles with depression and has to work three jobs to make ends meet, and how the father is not a constant presence in the child's life.

After researchers asked the teachers and staff to rate the severity of the child's behavior, they found a difference according to race: White teachers and staff seemed to be easier on the students they thought were black than black teachers were. Black teachers and staff recommended more days of suspension than white teachers did. (Black teachers recommended longer suspensions for both black and white children.)

The white teachers seemed to hold the black preschoolers to a lower standard for behavior than the black teachers did. It may be that white teachers hold an implicit bias that black children are more likely to misbehave, so hearing a vignette of a black child with challenging behavior is not viewed as severe or out of the ordinary, according to the study.

"Low expectations for students (of any age) can have very devastating impacts," said Gilliam. "We know this from decades of research on this topic. Children tend to live up to our expectations -- and they also tend to live down to them."

Another fascinating finding was the impact of biographical information and whether it might lead to a more empathetic response on the part of teachers and staff. It did -- but only when the race of the child was the same as the race of the teacher or staff member.

The findings match a lot of the research on empathy, said Gilliam. When we hear about the misfortunes of others, it tends to create an empathetic response in us if we feel some connection to the person through some shared experience or shared racial or cultural identity, he said.

"If we feel very different from the person who has these misfortunes, it tends to increase our negative stereotypes about them because now we say, 'Aha, that's the reason why. But of course, we can't help this black child with the bad behavior because it all starts with the parents. There's your proof.' "

If you have a shared connection, you might see that same information and think differently, said Gilliam. "You see the same information, and you say, 'Oh, maybe there's something to do with their parents and their family and how things are going on in their family. Now I understand it.' "

There's more work to do

Gilliam started designing this study in 2007-08, when he began working with the Congressional Black Caucus, which was concerned about the disproportionality of black children in preschool expulsions. It took years to find funding for the study, which was provided by the W.K. Kellogg Foundation. He and his fellow researchers began collecting data only in the past year.

Release of the findings was requested by the US Department of Health and Human Services, according to Yale.

After presenting the findings at a conference in Washington, Gilliam said he didn't think any of the officials in the audience were surprised to hear that racial bias appears to be happening as early as preschool.

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"I think that a message that a lot of them took from it is that's it's not just enough to get our teachers and our parents more connected. We have to help our teachers and our parents be able to understand what to do with that connected information once they get it," he said. "And if somebody who may feel very different from you, they will hear your strife and your struggles and your challenges, if they don't relate to you, it could actually make them feel overwhelmed, and not because these are bad people. We all have implicit bias."

What ultimately is needed, he believes, is helping teachers, staff, parents and administrators, working in early education, elementary education and beyond, better understand the implicit bias we all have.

"What we really probably need to be doing is helping teachers better understand it and feel more comfortable around it and feel more comfortable talking about race in our schools and even in our preschools."