Referring to a psychologist as a "shrink" can be considered impolite or disrespectful in some contexts. The term "shrink" is an informal slang that originated from "headshrinker," which was historically used to describe certain tribal shamans who practiced head binding and other rituals. Over time, it has been used colloquially to refer to mental health professionals, particularly psychiatrists and psychologists.
While some mental health professionals might not take offense to the term and may even use it humorously themselves, others could find it derogatory or dismissive. It's essential to be sensitive to how individuals identify and what terminology they prefer. Using proper titles such as "psychologist" or "doctor" (if they hold a doctorate) is more respectful and appropriate in most professional settings.
If you are unsure about how a mental health professional prefers to be addressed, it's best to ask them directly or stick to using their professional title. Respecting their preferences demonstrates consideration for their profession and the work they do.