Talking to oneself is something people do to hear out their own ideas. Most people learn to internalize this dialogue and shield its message from those watching. But in so doing, they short-circuit a channel in the brain for connecting emotionally to your own ideas. The enthusiasm of body, face, and mannerisms is self-contagious. When we actually talk to ourselves in excited tone and cannot contain the physical energy boiling within, we allow our bodies to tune in to our emotional state, fueling a positive-feedback loop that again encourages the message's emotional content. When we only speak with internal dialogue, this channel cannot be used, and the message is stripped somewhat of its emotional content.
I believe people should feel comfortable expressing their energies physically. We are taught from a young age to sit still and absorb information like a sponge, but that's not how our bodies are designed. If someone is telling you a complicated mathematical concept, feel free to visualize it with your hands. If someone is excitedly telling you about their day, reflect their enthusiasm back with some fist pumps into the air. Walk around the house while on the phone. Fidget in your seat at a lecture, or just get up and do something in the back of the room. Share your whole self with others during conversation, not just your eyes, ears, and mouth.
