You're reading a lot into something they didn't even claim. They explain why they had to choose a specific race in the following paragraph: > It was essential

You're reading a lot into something they didn't even claim. They explain why they had to choose a specific race in the following paragraph: > It was essential to keep the race and gender of the subjects constant to test my central question: How would reactions to my sanctioning message change based on the race of the bot sending the message? Why they chose people who were white shouldn't really matter as their conclusion was not "white men are racists". It was just something that had to be kept constant and grouping on race is not something unfamiliar for researchers, especially since in this case the whole experiment was based on the races of the sender and receiver. (Also note that it's much easier to distinguish between black and white rather than if they made the profile pictures different shades on the Fitzpatrick Scale)