you should only do research if you like it. if you dont like it you'll know and it will be horrible. you should do something that you really like doing, that way it wont be about how many hours you suffered through but how many years you enjoyed doing it
It doesn't matter what kind you do. I asked an adcom member about doing psych research since I'm a psych major, and he said it was completely fine. They just want to see that you're somehow learning the scientific method. Pick something you're interested in or else you'll be miserable.