Why is it so comforting to talk at a gravesite to a lost loved one?

I think we all have done this, will do this, or have at least thought about doing this, when a loved one dies. i just watched a movie where two men were talking at a gravesite to the same woman and child. one was the husband, the other was their father. both men had their own private conversations with their deceased family.Question: is there really any communication, when people openly talk at the gravesite of a loved one or is this strictly a psychological situation?