This behavior eventually feeds back into the evolution of the design of social organs. In addition to those five situations where social ambiguity seems to be used most, another deserves separate treatment. Generally, if one is well up the social scale, one can afford to become aloof. By giving a signal of unconcern and independence, the transmitter communicates that there is no doubt that he or she is the dominant. There is a tendency in us to equate twitchy, flexible mouths or eyes, the mobility of which facilitates communication, with weakness.
Puppies are open and expressive, old dogs sober and aloof.
This is a common behavioral trait among many animals - subordination tends to result in more open communication. Children reared in homes with lots of love and a modicum of permissiveness are much more open than adults. Interestingly enough, greater openness is also a characteristic of absolutely rock-bottom social classes. If you are as opaque as you can be, you may avoid trouble and gain some privileges, but then again you may miss some important information or a potential friend. We really don't want Randolph for a new director - he told me himself that he cheats on his income tax and married Marge mainly for her social position.