They called the cops on him. ‘Friends’ spat in his Coke. 20 people, including Van Jones, Angélique Kidjo, and Montel Williams, share the first time they realized their skin color mattered. Share your own story with #realizediwasblack http://cnn.it/2kbT1ap

When was the first time you realized your race matters in terms of how people treat you?

That was the question CNN posed to several black celebrities. The stories vary dramatically, from encounters with police officers to interactions during elementary school sports.

Here are some of the stories:

Jason George , actor: “I remember being at school, fifth grade, playing football with a bunch of the kids. In elementary school at least, I was one of the bigger kids. And so I tackled this one kid who was one of the smaller kids at the time. He was upset and maybe embarrassed and he called me a ni**er. I kinda blacked out. I honestly remember nothing in the next few seconds. And by the time I actually remember what was going on, his face was really close to mine, and I realized that he was purple. And I realized that he was purple because my hands were around his neck and he wasn’t breathing. And suddenly I was freaked out. This kid made me lose control. This word. This one word had complete and utter control over me in some ways.”

, actor: “I remember being at school, fifth grade, playing football with a bunch of the kids. In elementary school at least, I was one of the bigger kids. And so I tackled this one kid who was one of the smaller kids at the time. He was upset and maybe embarrassed and he called me a ni**er. I kinda blacked out. I honestly remember nothing in the next few seconds. And by the time I actually remember what was going on, his face was really close to mine, and I realized that he was purple. And I realized that he was purple because my hands were around his neck and he wasn’t breathing. And suddenly I was freaked out. This kid made me lose control. This word. This one word had complete and utter control over me in some ways.” Angélique Kidjo , singer: “I moved to France in 1983. One morning, I woke up and I was going to school. I crossed my neighbor that was coming back from the pastry store. At one point we crossed paths, and I say, ‘Bonjour.’ And then he freezes. He was like, looking at me like, trying to escape like I was just going to stab him. And it was so shocking and so painful for me.”

, singer: “I moved to France in 1983. One morning, I woke up and I was going to school. I crossed my neighbor that was coming back from the pastry store. At one point we crossed paths, and I say, ‘Bonjour.’ And then he freezes. He was like, looking at me like, trying to escape like I was just going to stab him. And it was so shocking and so painful for me.” Van Jones, CNN commentator: “There was a young white girl sitting next to me and she reached for the Coke can. And the guy said, ‘No. No. No. Don’t drink that.’ It felt a little awkward, but I drank my Coke and we kept talking. And then we got on the buses and we went back home. The young white girl started crying, and I asked her what was wrong. And she said, ‘They told me later that everybody in the room spat in your Coke while you were outside. And that’s why they didn’t want me to drink out of that can. And I’m so sorry.’”

Check out the full stories in the video above or at CNN’s website.

The stories are heartbreaking, reflecting on the kind of racism that black Americans face in their day-to-day lives. But these stories don’t just reflect a few anecdotes from a handful of celebrities. Study after study has uncovered that much of the racial bias noted in these stories is fairly prevalent in America — suggesting that the people CNN interviewed are far from alone in their experiences.

Studies find persistent signs of racism in the US

As part of a study published in the Journal of Personality and Social Psychology in 2014, researchers studied 176 mostly white, male police officers, and tested them to see if they held an unconscious “dehumanization bias” against black people by having them match photos of people with photos of big cats or apes. Researchers found that officers commonly dehumanized black people, and those who did were most likely to be the ones with a history of using force on black children in custody.

In the same study, researchers interviewed 264 mostly white, female college students and found that they tended to perceive black children ages 10 and older as “significantly less innocent” than their white counterparts.

“Children in most societies are considered to be in a distinct group with characteristics such as innocence and the need for protection,” Phillip Goff, an author of the study, said in a statement. “Our research found that black boys can be seen as responsible for their actions at an age when white boys still benefit from the assumption that children are essentially innocent.”

Other research suggests there can be superhumanization bias at work, as well, with white people more likely to associate paranormal or magical powers with black people than with other white people. And the more they associate magical powers with black people, the less likely they are to believe black people feel pain.

Another study found people tend to associate what the authors call “black-sounding names,” like DeShawn and Jamal, with larger, more violent people than they do “white-sounding names,” like Connor and Garrett.

“I’ve never been so disgusted by my own data,” Colin Holbrook, the lead author of the study, said in a statement. “The amount that our study participants assumed based only on a name was remarkable. A character with a black-sounding name was assumed to be physically larger, more prone to aggression, and lower in status than a character with a white-sounding name.”

This is just a small sampling of the research. But no matter how these kinds of studies are conducted, there’s a clear bias going on: Many Americans tend to associate black people with criminal behavior and violence.

These biases can seriously impact people’s lives

Racial biases can obviously affect the day-to-day interactions of black Americans, as the CNN video above shows.

But they can have perhaps deeper impacts as well, including for people’s job prospects. In one study, researchers sent out almost entirely identical résumés — except some had stereotypically white names and others had stereotypically black names. The white names were 50 percent more likely to be called back for interviews.

These biases also may contribute to racial disparities in police use of force. An analysis of the available FBI data by Dara Lind for Vox found that US police kill black people at disproportionate rates: Black people accounted for 31 percent of police killing victims in 2012, even though they made up just 13 percent of the US population. Although the data is incomplete because it's based on voluntary reports from police agencies around the country, it highlights the vast disparities in how police use force.

Some of these disparities are explained by socioeconomic factors — such as poverty, unemployment, segregation, and neglect by the police when it comes to serious crimes — that lead to more crime and violence in black communities. As a result, police tend to be more present in black neighborhoods — and therefore may be more likely to take policing actions, from traffic stops to arrests to shootings, in these areas.

But these structural disparities don’t appear to explain everything. A 2015 study by researcher Cody Ross found, “There is no relationship between county-level racial bias in police shootings and crime rates (even race-specific crime rates), meaning that the racial bias observed in police shootings in this data set is not explainable as a response to local-level crime rates.” That suggests that perhaps other factors are involved in the disparities seen for these shootings, including racial bias.

Before they experience these kinds of racial disparities, though, many black Americans will likely see racism firsthand in their day-to-day lives — and CNN’s video offers several ghastly examples of that prejudice.

Watch: The myth of race, debunked