If we are all concentrating on the events on the screen, even the slightest activity that could possibly be interpreted as important to the group's survival is transmitted by the individuals in unconscious verbal or body language. We can all remember at least one scary scene from one of our favorite movies which caused us to expel a small verbal gasp or body preservation movement. These small verbal excitations and body movements, if totaled together, can create a group communication representing a warning of danger. My point here is that the communal communications gave directional signals of danger avoidance to help in survival mechanisms. In short, when an entire audience gasps in fear or cheers for joy, I hazard to guess that it is a form of evolved intragroup communications.
Group communication is just one form of group survival information.
The survival information that stays with us the longest are the instructional lessons taught to us by family and friends. These lessons usually concern behavioral techniques, moral and cultural guidelines, and specific mechanisms necessary for survival. Our family and friends receive the greatest benefit from our survival, and because of that, they usually are the ones that watch over us and inculcate us with information that they feel is most important. In fact, our successful evolution from the savanna plain and the rain forest trees evolved from, first, helping our family members, and then helping others of our same species in a behavior mechanism we call altruism. Unfortunately, along with the moral things we need to know come the dredges of our jungle environment concerning prejudices.