On every school day in 2016, some 250 preschool children across the country were suspended or expelled for bad behavior, according to a new analysis of national data, and black children were more than twice as likely to be affected than other children.

In total, about 50,000 preschoolers — kids who are 3 and 4 years old — were suspended from both public and private preschools at least once in 2016, and an additional 17,000 are estimated to have been expelled, according to findings from the nonprofit Center for American Progress.

Black children were 2.2 times more likely to be suspended or expelled than other children, the analysis said, and boys were given 82 percent of the suspensions and expulsions, even though they represent 51 percent of the population of preschool children.

The D.C.-based organization analyzed data from the 2016 National Survey of Children’s Health, which is conducted by the Data Resource Center for Child and Adolescent Health, a nonprofit national data resource. The data was released in September.

Rasheed Malik,  a policy analyst for the Early Childhood Policy team at the Center for American Progress, wrote:

These disciplinary rates are particularly shocking, since suspending and expelling young children has not been shown to produce positive behavioral results. Quite the opposite, such practices can often intensify the challenges faced by these children and their parents, and have even been discussed as the first stage in a preschool-to-prison pipeline.

The findings are similar to those from federal data released last year, which found that the nation’s public schools suspended significantly fewer students in 2014 than they did in 2012, but racial gaps persisted. According to that data for the 2013-2014 school year, black preschoolers were 3.6 times more likely to receive at least one out-of-school suspension as white preschoolers.

Earlier this year, Malik wrote about why disciplining preschoolers this way is harmful, saying that it can turn normal child behavior into a pathology. He wrote:

Children at the young ages of 3 or 4 often test boundaries and act out, particularly when adjusting to new social environments such as preschool. According to the American Academy of Pediatrics, it’s perfectly normal for a preschooler’s frustration or anger to manifest as physical conflict. When caregivers correct this ordinary behavior in a way that promotes empathy, it’s a healthy part of a child’s social development. Labeling a young child as violent or disruptive and calling parents to pick up their child sends the wrong message to the child, and it could even lead to unnecessary medical or psychological interventions.

It can also be driven by implicit racial bias, he wrote, citing a Yale University study that used sophisticated eye-tracking technology and found that “preschool teachers tend to more closely observe African American children than white children when they are expecting challenging behavior.”