When we are uneasy, stressed, or in a tense discussion over dinner, we often shut down. We may retreat, physically or emotionally, get defensive, or lash out in anger. Learning to work with this automatic response in a productive manner is a crucial life and relationship skill. This is one of the most complicated and common conversations I have with my clients; both the concept of self-regulation, and the work itself, are very challenging.
This is an excellent article by Pema Chödrön, a Buddhist teacher, discussing exactly this topic. She explains the Tibetan concept of shenpa, the automatic urge to shut down or emotionally protect ourselves in other ways. She discusses how we can learn to sit with unease, rather than getting hooked or triggered and then doing/saying things we will regret later.