Stopping to engage beyond a minimum of respect and politeness, that is, controlling their (emotional) reactions towards the client, is a standard tool of psychologists. I remember being all in tears during a session, and my therapist appeared unsettling unaffected. Instead of entering my self-pity, she appealed on my self-responsibility. It worked.
But try this to your wife. If she is clever, she will demand reinforcement. So instead of changing herself, she will just accuse you being impassive, unresponsive or insensitive.