Facebook's internal research found that it encouraged polarization, but Mark Zuckerberg and other top executives rejected ideas aimed at fixing the problem, The Wall Street Journal reported.
One report concluded that Facebook's algorithms "exploit the human brain's attraction to divisiveness," according to The Journal.
But Zuckerberg and Facebook's policy chief, Joel Kaplan, repeatedly nixed proposed solutions because they feared appearing biased against conservatives or simply lost interest in solving the problem, The Journal reported.