Cognitive bias - Confirming the attitudes of your peers Is there a well-studied cognitive bias that describes a situation in which a person expresses a positive attitude towards something because his or her's friends have a positive attitude about that thing as well?

I am speaking mostly in the context of social networks - people pressing the "Like" button on Facebook because they saw that their friends have liked a certain something as well.

I've read about the Bandwagon effect but that doesn't quite seem to fit my description exactly - mostly because it seems to apply to how one's beliefs are influenced by one's peers.

What I am looking for is something that describes the situation in which a person likes something independently of what others tend to think, but the person's decision to actually share that liking attitude to the world is triggered by seeing that others have shared that positive attitude already.

Also, if you have a list of articles on this subject, I would be very grateful if you shared them.
I think what you are describing here is the balance theory by Fritz Heider.

The following extract is from Online Psychology Laboratory, social balance article :


  Heider's Balance Theory (Heider, 1946) primarily focused on
  perceptions of relationships in the form of a triad. This triad,
  typically involving two people (the perceiver and another person) and
  an object of their attitudes, included three relationships. Heider
  (1958) labeled these attitudes as "sentiments," personal evaluations
  of other entities that underlie people's actions. A triad of
  attitudinal relationships is considered balanced if all three
  relationships are positive, or if one is positive and two are
  negative.