But what does physiology have to do with anything? The problem was that the disasters showed all the signs of arousal — of being in fight-or-flight mode — in their relationships. Having a conversation sitting next to their spouse was, to their bodies, like facing off with a saber-toothed tiger.
Even when they were talking about pleasant or mundane facets of their relationships, they were prepared to attack and be attacked. This sent their heart rates soaring and made them more aggressive toward each other. For example, each member of a couple could be talking about how their days had gone, and a highly aroused husband might say to his wife, “Why don’t you start talking about your day. It won’t take you very long.”