Trust kicks in on remarkably simple cues. We’re far more likely, for example, to trust people who are similar to us in some dimension. Perhaps the most compelling evidence of this comes from a study by researcher Lisa DeBruine. She developed a clever technique for creating an image of another person that could be morphed to look more and more (or less and less) like a study participant’s face. The greater the similarity, DeBruine found, the more the participant trusted the person in the image. This tendency to trust people who resemble us may be rooted in the possibility that such people might be related to us. Other studies have shown that we like and trust people who are members of our own social group more than we like outsiders or strangers. This in-group effect is so powerful that even random assignment into small groups is sufficient to create a sense of solidarity.