To summarise: when people need to react to something other people are doing - such as when a crowd is caught in a stampede - we can either take the time to research exactly what's going on, or we can make a snap judgment based on what we see in others' actions. Part of why people believe fake news and don't fully research the stories, some researchers proposed, could therefore be a hard-wired, time saving, and generally useful shortcut to getting information based on what the crowd is doing.
About Natural News (owned and operated by Mike Adams), which had been banned from Facebook and what I found really informative was that
Mike Adams, the owner of Natural News and author of the story about Sparta and antifa, has dozens of other websites. Rory Smith, a research manager at First Draft, an organization that studies the spread of misinformation, found more than 200 domains that appear to be related to Natural News.
"It looks like each of these websites has the exact same layout," Smith said in a message. "So Mike Adams has expanded his junk news empire."
Some of those sites, like Collapse.news and Chaos.news, have also published the story about antifa groups and Sparta. Others, like Racewar.news, have posted different stories about Black Lives Matter protests. Some even impersonate legitimate media outlets, like Snopes and the Washington Post.