We can have as many friends as we want but only half of those so-called friends consider us as their own friend. According to a new study published on March 22 in the journal PLoS One, this shows that we are generally bad at picking friends.

“Our difficulty determining the reciprocity of friendship significantly limits our ability to engage in cooperative arrangements,” says Erez Shmueli from Tel Aviv University’s Department of Industrial Engineering. “We learned that we can’t rely on our instincts or intuition. There must be an objective way to measure these relationships and quantify their impact.”

The researchers from the Tel Aviv University and the Massachusetts Institute of Technology claim that knowing our true friends would lead to stronger social influence. This stronger social influence helps generate progress that will impact our lives positively.


Friends on a picnic. Credit: Pixabay/Unsplash

They had to create an algorithm with their data that looked into several objective features of friendship, which is the number of common friends or the total number of friends one has. They concluded that there are two types of friendship: one is reciprocal, where persons feel the same way toward each other and the other is unidirectional, where one’s “friend” does not actually feel the same way as the other.

The researchers’ friendship algorithm accurately determined that most of us believe that our friendship is reciprocal. Sadly, it turns out we have been blinded by this belief all along.

“We found that 95 percent of participants thought that their relationships were reciprocal,” adds Shmueli. “If you think someone is your friend, you expect him to feel the same way. But in fact, that’s not the case — only 50 percent of those polled matched up in the bidirectional friendship category.

The new study involved analysing data from earlier research that explored reciprocal relationship and its effect on human behaviour. They added data through their own survey of 600 students from Israel, the US and Europe.