9. Emphasize your shared values
According to a classic study by Theodore Newcomb, people are more attracted to those who are similar to them. This is known as the similarity-attraction effect. In his experiment, Newcomb measured his subjects' attitudes on controversial topics, such as sex and politics, and then put them in a University of Michigan-owned house to live together.
By the end of their stay, the subjects liked their housemates more when they had similar attitudes about the topics that were measured.
If you're hoping to get friendly with someone, try to find a point of similarity between you two and highlight it.
10. Casually touch them
This is known as subliminal touching, which occurs when you touch a person so subtly that they barely notice. Common examples include tapping someone's back or touching their arm, which can make them feel more warmly toward you.
In "Subliminal: How Your Unconscious Mind Rules Your Behavior," author Leonard Mlodinow mentions a study in France in which young men stood on street corners and talked to women who walked by. They had double the success rate in striking up a conversation when they lightly touched the woman's arms as they talked to them instead of doing nothing at all.
In a University of Mississippi and Rhodes College experiment that studied the effects of interpersonal touch on restaurant tipping, waitresses briefly touched customers on the hand or shoulder as they were returning their change. As it turns out, they earned significantly larger tips than waitresses who didn't touch their customers.
In one study, nearly 100 undergraduate women looked at photos of another woman in one of four poses: smiling in an open-body position, smiling in a closed-body position, not smiling in an open-body position, or not smiling in a closed-body position. Results suggested that the woman in the photo was liked most when she was smiling, regardless of her body position.
12. See the other person how they want to be seen
People want to be perceived in a way that aligns with their own beliefs about themselves. This phenomenon is described by self-verification theory. We all seek confirmations of our views, positive or negative.
For a series of studies at Stanford University and the University of Arizona, participants with positive and negative perceptions of themselves were asked whether they wanted to interact with people who had positive or negative impressions of them.
The participants with positive self-views preferred people who thought highly of them, while those with negative self-views preferred critics. This could be because people like to interact with those who provide feedback consistent with their known identity.
Other research suggests that, when people's beliefs about us line up with our own, our relationship with them flows more smoothly. That's likely because we feel understood, which is an important component of intimacy.