Holding my chin while I’m trying to think deeply may not be necessary, but it seems to help.
When I’m trying to listen, on the other hand, shutting my mouth is more than helpful. It’s absolutely essential. So is clearing my mind, and so is focusing my attention – sort of like deep thinking. All that is a lot of work, so we don’t experience a great deal of it around us.
Here is how it works: When I am in conversation and, shutting my mouth, put my hand to my chin, I am signaling my partner in that situation that I am thinking (maybe deeply) and focusing my attention.
If, at the same time, I continue looking at the other person, they will tend to conclude that I am taking them seriously and paying attention to what they’re saying.