This is well said:

Feeling sympathy for each others’ hardships is part of a healthy friendship. If someone you know is feeling lonely or isolated, inviting them along to meet your other friends can not only help them feel more included, it can also make your whole social circle feel better:

Unsurprisingly, people at the periphery of a network have fewer friends and are more likely to be lonely. And yes, that loneliness can flow back three degrees to you. (And no, you can’t easily track these people down and kick them out of your network.) Know what you can do? Introduce your friends to each other.

We’ve already talked about how making introductions can be a great networking tool. The same principle applies to your social life. If you know awesome people, but you have friends on the periphery of your social circle who feel left out, introducing them and bringing them along helps raise the entire group.

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