We know that the shootings of unarmed black men, women, teenagers and children are the violent outcomes of irrational white fear. To paraphrase author Claudia Rankine, “because white people can’t police their imaginations, black people are dying.” A new study finds the racial stereotypes and discrimination that lead to numerous black-white disparities, from education attainment to police violence and mass incarceration, begin long before adulthood and adolescence. Even the youngest black children—in particular, boys—are overly scrutinized and treated with undue suspicion.

Researchers from the Yale Child Study Center found that implicit bias—the unconscious prejudices and stereotypes that inform our attitudes and interactions with others—affects how teachers treat African-American male students as young as 4 years old. The study, which included 135 pre-K educators, was conducted at a “large annual conference of early care and education professionals.” The educators were told that researchers were “interested in learning about how teachers detect challenging behavior in the classroom.” Before being shown a series of 30-second video clips, they were provided with a simple set of instructions:

“The video segments you are about to view are of preschoolers engaging in various activities. Some clips may or may not contain challenging behaviors. Your job is to press the enter key on the external keypad every time you see a behavior that could become a potential challenge. Please press the keypad as often as needed.”

The study subjects were advised that “sometimes [spotting misbehavior] involves seeing [it] before it becomes problematic.” The video clips included four children—a black girl, a black boy, a white girl and a white boy—partaking in everyday preschool activities. The one detail subjects were left in the dark about was the fact that “none of the videos [actually] contained challenging behavior.” Researchers used eye-tracking software to determine where the teachers, primed to look for potential trouble and troublemakers, fixed their gaze most intently. The intersection of race and gender was a key determinant of where educators looked; they kept their eyes on the black children more than the white children and gave more attention to boys than girls. Out of all four children, the teachers spent the most time studying the black boy for subtle signs of emerging misconduct.

It’s worth noting that these teachers, almost all of whom were female, were both white (66.7 percent) and black (22 percent). The across-the-board hypervigilance of the black boy is proof that to some degree, regardless of our own race, we all internalize the American dominant culture’s narrative of black criminality.

When directly asked which kid needed the most negative attention to proactively forestall bad behavior, 42 percent of teachers identified the black boy. The numbers dropped off from there, with 34 percent indicating the white boy, 13 percent the white girl and 10 percent the black girl.

In another study section, early childhood educators were asked to read a short story involving a misbehaving 4-year-old, who they were then advised to pretend was one of their students. Though gender and race were not explicitly mentioned, both were implied by the character’s name, given either as Latoya, Emily, DeShawn or Jake. Childish infractions described in the vignette included difficulty napping, speaking loudly or out of turn, taking other students’ toys, and hitting classmates or instructors. In select cases, teachers were provided the following information about the imaginary student’s home life in an effort to determine whether it might impact their conclusions:

[Child] lives with his/her mother, his/her 8- and 6-year-old sisters, and his/her 10-month-old baby brother. His/her home life is turbulent, between having a father who has never been a constant figure in his/her life, and a mother who struggles with depression but doesn’t have the resources available to seek help. During the rare times when his/her parents are together, loud and sometimes violent disputes occur between them. In order to make ends meet, [child's] mother has taken on three different jobs, and is in a constant state of exhaustion. [Child] and his/her siblings are left in the care of available relatives and neighbors while their mother is at work.

The teachers were asked to assign a rating of 1 to 5 in three areas: severity of the child’s misbehavior; level of educator hopelessness (i.e., “the degree to which they felt that nothing could be done to improve the behaviors”); and likelihood the teacher would recommend suspension or expulsion. In cases where either was suggested, they were also asked to state the number of days that would fit the bill. It’s here that a curious trend emerged, one that has everything to do with expectations.

White teachers viewed the behavior as more severe when the child was depicted as white, but less so when the 4-year-old was imagined to be black. Researchers suggest that this correlates with previously studied racist notions and stereotypes around black behavior. That is, if you already believe that black children, black boys in particular, are more likely to behave poorly (and the scrutiny teachers gave black students suggests that’s precisely what they believed) you’ll probably find their misbehavior less surprising, disappointing or problematic than with white students, from whom you expect better.

Conversely, black teachers saw black students’ misbehavior as more severe than their white cohorts. Researchers suspect they unconsciously held black students to higher standards than participating white teachers did, and regarded black student misbehavior as a greater concern than for white students. This, the researchers note, was consistent with previous studies cited.

In contrast with previous scholarship, which found that “Black students are rated as less disruptive and are suspended less often when they are rated by black teachers than when they are rated by other-race teachers,” black teachers in the Yale study “recommended expelling or suspending children more days than white participants.” Study authors connect that surprising finding with theories about black cultural notions of corporal punishment, for example, as a method of toughening up children for encounters with racism, discrimination, and other forms of anti-black oppression and even violence.

Just as black parents feel the “need to prepare [black] children for, or protect them from, a harsh world,” Yale psychologist and study lead Walt Gilliam told the Washington Post, “[i]t seems possible that the black preschool teachers may be operating under similar beliefs… that black children require harsh assessment and discipline.”

There was another fascinating aspect of the study. In cases where teachers were given background information on the naughty child, their level of empathy increased only when teacher and student were of the same race. When the student and teacher were of differing races, the teachers actually viewed the child’s behavior as worse when they learned of her or his troubled home life. Empathy, it seems, has difficulty crossing racial boundaries.

All of this is massively important. Numerous studies show that students who are suspended or expelled are more likely to do poorly in school, to drop out before graduation, and to enter the criminal justice system. That’s the school-to-prison pipeline in a nutshell, and the Yale study suggests teacher biases begin propelling black boys along the carceral route at a startlingly young age. The Yale psychologists open their report by pointing to investigations showing black preschool-age children are 3.6 times more likely to be suspended than white preschoolers. Though black kids make up just 19 percent of all pre-K students in this country, they are 47 percent of those who are suspended at least once, though frequently more often.

The teachers who participated in the Yale study are not unique in their implicit biases against black kids. Their deeply held attitudes are actually closely in keeping with what we already know about the pervasiveness of racism and implicit bias, and the devastating impact both have on the lives of black children in this country. Previous studies have found that black children are seen as older and less innocent by many white Americans; that they are more likely to be placed in correctional facilities even when they commit less crime than white teens; that they are more likely to be tried as adults than white youngsters; and that they face longer sentences for the same crimes young white offenders commit. Gilliam rightly states the study is more evidence that anti-black racism is inextricable from black lives and American institutions, and that it poisons every aspect of the black American experience and outcomes.

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