Hell no.
No it is not!!! I worked on a neuroscience research project where we had to measure each subject’s brain activity and run a hearing test AND we paid each subject. We never even considered asking for their SSN, so either the person reaching out to you is a scam artist or they are needlessly obtaining more info from you for no reason.
It’s probably a study to see how much secure information you can get from a person just by pretending to be an authority like a professor doing a university study.
Even if it was I still wouldn’t.
Don’t do it