Source: Sport and Exercise Psychology: A Critical Introduction — Aidan Moran
In everyday life, we tend to see any collection of people as a group. However, social psychologists use this term more precisely. In particular, they define a group as two or more people who interact with, and exert mutual influences on, each other (Aronson, Wilson and Akert, 2002). It is this sense of mutual interaction or inter-dependence for a common purpose which distinguishes the members of a group from a mere aggregation of individuals.
I don't think that "sense" mean "meaning". I think that it doesn't fit the context.
Does "sense" mean "idea" or does it mean "feeling"?