To me it's not that this paper is going to end up in any big medical journal. It surely won't. It's what it represents in other costs. Thousands of students go through this Psych class a year. This research project is fully representative of what this professor believes. My daughter has students in her class who are going on to become psychologists, social workers, therapists, and others in the Pre-med program. This professor's beliefs are going to influence how they treat and interact with people like us in the future.
Firstly I would not respond or engage at all. All surveys have a percentage of people who don't respond and you are perfectly entitled to be in it. If you decide to respond because of the credit blackmail thing (which is disgraceful and should be challenged or ignored too) then why don't you just make up whatever answers you feel like, including those that would be most likely to bugger up the professor's pet theory? You have no duty to answer any questions at all, and if they blackmail you into it under threat of your daughter's credits, any answers you give are under duress and unreliable anyway, so you can decide how or in what way they are unreliable. If they won't let you exercise your right not to respond, exercise your right to be an outlier. Fuck 'em.