The course is History of Psychology, a senior-level required course that reviews the intellectual history of Western science but focuses on psychology. One of the ideas we explore, of course, is the theory of Sigmund Freud. Although his theory does not enjoy wide acceptance today in American psychology, it is still quite influential.
It's a dynamic theory in the sense that it attempts to explain why we behave the way we do. He describes the inherent conflict between SUPEREGO (with its moral teachings and conscience) and ID (with its desire for immediate gratification). To resolve that conflict, your EGO often engages in any one of a number of activities known as defense mechanisms, each of which operates at the unconscious level. You're not aware of them, nor are you aware of what your ID is up to. Defense mechanisms are irrational in the sense that they deny, distort, hide, etc. the reality of the conflict. I'm oversimplifying, and there is much more.
The theory, however, is quite weak from a theory construction perspective. It does not make testable predictions, and where you might see predictions, it's not clear. For example, depending on how your toilet training unfolded, you might become a very neat person or you might become a very messy person. Well, that's handy. It's always right - which is to say it has no truth value. It's all post hoc. Seeing someone who is messy (or neat), it suggests certain things happened in childhood, but it doesn't go the other way. For a theory to be useful, it has to be disprovable. This one isn't, and many of it's concepts are not empirically verifiable.
Which brings us back to the Cloak of Invisibility. What the exercise is attempting to do is remove whatever effects that SUPEREGO might have - now that you won't get caught, and without the conflict between ID and SUPEREGO, EGO doesn't have to engage in any defense mechanisms. You're likely to be honest about what you'd do, rather than denying it or repressing it. You're unconscious desires become conscious, and maybe we have empirically supported the notion of ID.
What is mentioned the most?. The most common answers revolve around surveillance, pulling pranks, or outright illegal activity. No one ever talks about doing a nice thing. Almost never anyway.
"I'd spy on my boyfriend to see what he really thinks or if he's faithful." Spying on sister, teachers, coaches, White House, gov't - you name it, and I've seen it listed. "I'd go see what it's like in the men's/women's locker room." Checking someone who was unclothed is very popular.
"I'd do weird things to try to scare my friends." Create havoc by floating objects in front of people. Mess with the CIA or FBI. Rearrange my friends' stuff. Make noises to disrupt sleep.
Then there is the illegal perspective. I've only seen punching someone in the face once (specifically, Nancy Pelosi). "I'd rob a bank" - which is frequent but occasionally is had a Robin Hood aspect to it. Mark all my loans as paid off. It's not always money; I see lots of theft of services - go stay and eat where I can't afford it, travel the world for free, explore Disney after hours.
So, what would you do if you had a Cloak of Invisibility for 48 hours.