- mice don't live as long as humans (a dead human is more years of lost life than a dead mouse)
- mice don't mourn each other, and these mice couldn't anyway because they'll all be dead soon
- in nature, mice typically die violent deaths anyway, so lab mice usually aren't suffering worse than a wild mouse would
- mice don't get sick and suffer for years, becoming a burden to their family and society
- mice don't fear their premature deaths for months or years
I mean, I can go on and on. Knowledge of the past and future gives humans a significantly greater propensity for suffering than other animals.
If aliens from Tralfalmadore were to adopt the same values, they might choose to experiment on humans because
- humans don't live as long as Tralfalmadorians
- humans don't mourn each other the same way Tralfalmadorians do, and these humans couldn't anyway because they'll all be dead soon
- in nature, humans typically die violent deaths anyway, so lab humans aren't suffering worse than a wild human would
- humans don't get sick and suffer for as long as Tralfalmadorians do
- humans can't predict their expiry date like Tralfalmadorians can
- mice don't live as long as humans (a dead human is more years of lost life than a dead mouse)
- mice don't mourn each other, and these mice couldn't anyway because they'll all be dead soon
- in nature, mice typically die violent deaths anyway, so lab mice usually aren't suffering worse than a wild mouse would
- mice don't get sick and suffer for years, becoming a burden to their family and society
- mice don't fear their premature deaths for months or years
I mean, I can go on and on. Knowledge of the past and future gives humans a significantly greater propensity for suffering than other animals.