Advancement, always.

That's probably because I'm a Nietzschean. And a Machiavellian. And a psychopath.

Still - advancement.

Reality isn't black and white, and I see no reason to present my opinions in black and white either. Advancement with a conscious mind to ethics seems reasonable to me.

It's a tricky one for me, because on the one hand you have something like the grossly unethical conduct of Nazi experimentation's which resulted in disability, disfigurement and the mental distress of a multitude of innocent people, but also advanced scientific and medical inquiry, namely the effects of certain gases and the treatment of hypothermia.

The same goes for the experimentation of animals. I suppose I'm a proponent of advancement if the participants weren't human, or extremely sentient, and that it supports a genuinely beneficial cause like the aforementioned treatment of illnesses. I'd draw the line where it comes to cosmetic purposes or financial gain for a small group of individuals, and the suffering of the participants greatly outweighed the benefits reaped from it.

In the case of which of the two is more important, I'd lean towards advancement.

The Stanford Prison Experiment probably isn't a good example to use since it was an extremely flawed and biased experiment. Everyone was behaving normally until they were told by the researchers to put on certain roles.

I suppose it depends how far you're intruding past "the line" compared to the use of the knowledge gained.

I mean, are these Nazi experiments on Eastern European/Jewish/"Undesirables" completely useless information or have these experiments, though obviously cruel and brutal, helped anyone? I would probably say no (definitely for Mengele's experiments regarding pain tolerances for different races).

But the experiments in OP are pale in comparison for the effects, and arguably have been a benefit to those with depression or other similar psychological problems through scientific understanding of the conditions. Otherwise we could still be throwing people with mental conditions in the old Victorian asylums, and treating them far worse through ignorance.

Advancement. You can't have advancement without trial and error, and blocking T&E blocks advancement.

Mengele did nothing wrong.