“Human beings operate in a very strange way,” says Catalina Toma, a University of Wisconsin professor who studies how the way we communicate is affected by new media technologies. More than we realize, she says, we use non-verbal cues such as facial expressions to determine whether someone can be trusted. (Of course, even judgments based on in-person interactions can be faulty; Neville Chamberlain famously came away from his first meeting with Adolf Hitler with “the impression that that here is a man who could be relied upon when he had given his word.”) Online, though, things are trickier. Non-verbal cues are removed, so we need to rely on other indicators. Toma says humans don’t manage this process very adroitly. “When you have little information about someone, we tend to fill in the blanks,” she says—more often than not in an unrealistic manner. “Filling in the blanks leads you to like someone without knowing much about them, which leads to an intensification of emotions,” says Toma. This explains, in part, why relationships can blossom online at a more accelerated pace than they would in person…

“When people are emotionally invested, they tend not to process in a cool or rational way anymore. They are inclined to disregard potentially suspicious information,” explains Toma. “People scan the environment for clues that confirm what they already believe” as opposed to the other way around. Now it’s now so hard to see how Te’o and Frampton could be so easily fooled.

The sheer magnitude of our online environment contributes, too. A study released in January by Ipsos Open Thinking Exchange, a culture and technology research center, found that the average social-media user under the age of 35 spends 4.2 hours every day engaging with people online. Being connected to so many people “generate this sense that you’re not alone, which can really mess with your perception of risk,” Kathleen Cumisky, a professor of psychology, gender and sexuality at the College of Staten Island, told The New York Times in a story about Sarai Sierra, the 33-year-old Staten Island woman who was found dead in Turkey earlier this year. It “lulls you into this sense of security because it is a world of your own creation.”