High variance in groups with different cultural norms. And, even within those groups, there is variance based on the level of trust within the group and the context of the conversation. Example: I like observing negotiation-heavy (implicit or explicit) conversations between two groups of people on deep or nuanced topics. If one group has folks 'interrupting' each other in a natural, accretive, iterative way, then it often means they have a high level of trust in each other and confidence.