63 Moments That Instantly Ended A Potential Friendship

Even though we are taught not to “judge a book by its cover,” it's hard not to do so. Moreover, we're not very open to changing our minds later; our initial impressions don’t fade easily from memory.

However, our tendency to make split-second decisions about people isn’t inherently bad, says Vivian Zayas, PhD, professor of psychology at Cornell University. It’s human nature and an evolutionary defense against those who might be dangerous to us.

“Humans are very social, so we want to know when we meet someone what that person is really about,” Zayas explains. “We are wired to do this, and we’ve become experts at gathering a wealth of information from people’s faces—things like gender and ethnicity, but also more subtle personality cues as well.”

For one of their studies, Zayas and her colleagues asked 55 participants to evaluate whether they’d be friends with four women based solely on headshot photographs. Each woman smiled in one photo and had a neutral expression in a second. The participants were also asked whether they thought these women were extroverted, agreeable, emotionally stable, conscientious, and/or open to new experiences.

But the key was that between one and six months later, the participants returned for a supposedly unrelated experiment and met one of the women whose photos they had previously judged. (Only four participants remembered seeing the woman before, and they were later excluded from the analysis.) Each participant spent 20 minutes with this woman, during which they played a trivia game and were instructed to get to know each other as well as possible.

After the interaction, the participants were asked the same questions about the woman’s personality traits—and interestingly, their responses showed a strong correlation with their previous judgments. Those who had guessed that the woman was likable and had appealing personality traits generally had positive impressions after meeting her. For those who had judged the woman negatively, their opinions tended to stick as well.

“What is remarkable is that despite differences in impressions, participants were interacting with the same person,” Zayas says. The results show that some changes in opinion did occur, but for the most part, people’s views didn’t waver.

The woman didn’t know how the participants had rated her photograph, so she didn’t enter the meetings with any biases of her own. But Zayas says it’s likely that participants’ initial impressions were reflected in their behavior, and that the woman picked up on those cues.

Those who had liked the woman in the photo tended to interact with her in a friendlier way. For example, they smiled and leaned in a little more, and their overall nonverbal cues were warmer.

“When someone is warmer, when someone is more engaged, people pick up on this. They respond in kind. And it’s reinforcing: the participant likes that person more,” Zayas adds.

So don’t worry if you don’t like everyone you meet. Forcing it might just make things worse.