Much of the social bonding in both Protestant and Mormon communities could come from the number of activities that members must attend, especially of Sunday mornings. Unless a Catholic has a child in CCD, the mass is all that is required. There are so many mass times that a certain social potential is lost.
When I was growing up in a very Protestant church, we had Sunday School and the morning worship service. There was quite a bit of social pressure to attend both, so that was the standard. Having one main service on Sunday morning meant that members learned other members. People had regular places they sat. You began to know right away if someone was missing. I would guess the same thing happens with Mormons with the three hours they spend in church on Sunday mornings.
For example, a couple of years after I moved to another state, I was back in my hometown for a visit, so I went to church. I got there early and took a seat in a pew. An usher came over and whispered something approximately “Mrs. Smith usually sits there.” I moved to another spot and the same thing happened. The third time was a charm. Nothing like that could happen in my parish.
We have a Saturday vigil and four masses on Sunday. People, including my family, bounce around on their mass times, so you really don’t know who is there and who isn’t. We don’t have everyone going to a mass sitting in Sunday school classes an hour before mass. People drive up, park, go into mass, and make bee lines for their cars when it is over. Unless we volunteer for special activities, we don’t have the bonding of being in small groups that dismiss, walk together into the church and have identities such as the John Doe Sunday School Class.
I know it’s true in my former faith community and believe the same would hold for Mormons that someone wanting to attend only the main service on Sunday would run into friendly and firm pressure to be there for more meetings.