Psychology and Sociology experiments are vital for research and the advancement of understanding how the human bran functions and often you can get paid to take part in these trials. They are generally a lot less risky than medical trials because they don’t require you to consume anything. But for the same reason they are paid significantly less.
The type of things you have to do may include filling out questionnaires, looking at a screen, group work, having your eyes scanned and lying in an MRI machine. The amount of time ranges from less than an hour to visits over weeks, months or even years.
These sorts of experiments or trials are often ran by universities in either the sociology or psychology department but sometimes by private companies. It usually involves you going to the university or lab in person but some times they are ran remotely.
If you are interested in taking part in such experiments try contacting your local university to find out if they are currently running any.