Three environmental cues that can be listed are: territory, lighting and sound.
The ways the three of them affect the expectations for communication are:
When it comes to territory, being close to someone will mean that this individual is friends with me, or has a close relationship. If the person takes his/her distance, I expect to be having a more formal conversation, or to be interacting with someone whom I'm not close with.
Lighting affects my expectations for communication in a way that if the light is low, I'll be expecting to have a more intimate conversation, specially with someone whom I have a relationship with.
And last, sound, if I'm in a noisy place I won't expect to have a serious conversation, I'll be expecting to have a more casual talk. In a quiet environment I can expect to have a serious talk.
