The electric-shock obedience experiment sent Stanley Milgram into infamy. It also was the catalyst for American Psychological Association to adopt ethical considerations when performing psychological experiments on people. Plus One
reports that a group in London re-ran the same experiment in a virtual
world and the results were eerily similar. The participants showed
comparable stress and anxiety levels. Their conclusions?

Our results show that in spite of the fact that all participants knew for sure
that neither the stranger nor the shocks were real, the participants who saw and
heard her tended to respond to the situation at the subjective, behavioral and
physiological levels as if it were real. This result reopens the door to direct
empirical studies of obedience and related extreme social situations, an area of
research that is otherwise not open to experimental study for ethical reasons,
through the employment of virtual environments

My conclusion?  I am not all that concerned with the world of obedience
studies but what I am concerned with is the empirical proof that a
virtual world can have a comparable emotional impact on is residents as
real world activities. This being said it lends additional support to
engaging in psycho-significant research and therapeutic activities in
the medium. For the human service sector it provides further credence
to the Asperger’s therapy work that is currently experiencing success in virtual worlds such as Second Life.