How about morality - can you construct an experiment to show that stealing is wrong or do you already know it is wrong before you start?
I don't know if this counts but I can first off show historically where stealing is bad for the community as a whole. As a rule it should be avoided based upon historical events. A community riddled with theft and other crimes is less enjoyable and prosperous as a whole. Polling data would indicate a lower quality of life..
Now is stealing morally wrong? I think "morally" is subjective, and in reality is a community cultural thing, moral = good for the community to have a certain quality of life as a whole. From this we come up with the basic laws of humanity
Stealing - is wrong because it creates strife in the community, potentially inviting more theft and annimosity. (as such it is judged to be morally wrong)
Sex out of marriage - Creates bastard children, who do not have fathers and a complete support system. (history has deemed this immoral because it hurts the community)
Sex with neighbors wife - Well this cretes strife, annimosity, fights, and vendettas. (bad for community again becomes morally wrong)
This is why almost universally most cultural norms over eons came up with moral codes that are passed down to children. They are based upon observation or people in antiquity.
An experiment would be simply any group of people thrust into these situations will have a higher incidents of escallating problems using observation you will be able to reproduce results over and over that allowing "immoral behavior" in the above catagories will result in a decrease in productivity and increase in injury:)
Morals are simply rules based upon human cultural experience and they are passed on by both the community and the parents. Many Morals are good for the community as a whole rather than the individual directly.
If I don't steal and we don't steal we will be more secure, If I don't kill and we dont kill then that benefits me in not being killed allowing my productivity to continue.
Immoral acts usually benefit the individuals self interest over the communities best interest.
"I want to sleep with my neighbors wife" I get a thrill but in the end it will likely (statistically) hurt the community.