Imagine you are having a party with you friend, and somebody introduce you two new friends. To your surprise, almost all your other friends show more friendliness to one of them. Will you also like that new friend more than the other?

According to a new Northwestern University study, you are likely to do that.
"This is important because often we are not explicitly thinking about the nonverbal signals that people display, so we could be picking up messages from the nonverbal signals in our environment that we are not even aware of." Said one of the researchers, Allison Skinner.
There is a popular Japanese expression on the internet, "Kuuki ga yomenai," English meaning "unable to read the atmosphere," which means the ones who cannot understand what others attempt to convey through nonverbal signals or verbal implications.

However, although some people may not know how to understand words that are not said out, humans psychologically follow what others do and tend to express a similar attitude.
The researchers showed participants a brief silent video of individuals interacting, and found that they acquired attitudes toward the individuals in the video based on the nonverbal signals that were displayed toward them.

What’s most interesting is that most of the participants did not think they were influenced by the video, and only 30% of them indicated the attitudes shown in the video influenced them.
"This has important implications for how people make sense of the nonverbal messages that they are exposed to in everyday life. These findings suggest that when we see people being less friendly toward one individual relative to another, we often attribute the unfriendliness to the target. Believing that we like them less because they do not seem to be very friendly, when in fact, it is others who were not very friendly to them." Said Skinner.

The study also showed that even in contexts in which people’s attitudes toward others are relatively neutral to begin with, the nonverbal signals that they observe can create new attitudes toward unfamiliar others.