And this is why we have human ethics committees at universities now!
Not only were these experiments unethical, there's continuing debate over their scientific value.
I know they weren't human experiments, but I feel that Harry Harlow's experiments on monkeys are right up there in terms of both cruelty and bad methodology.
Yes, luckily, psychological experiments are much more regulated now!
I can say I'm an expert, but it seems to me that even the old, unethical ones did have some scientific value. I think that all three mentioned experiments at least did confirm presumptions about situational depersonalization, obedience to authority, and conditioned fear. Of course, the methodology was far (FAR) from perfect, making the results hardly measurable.
I agree with you that the experiment on social isolation performed on monkeys were, at least, as cruel as the above-mentioned three conducted on humans. :/