This includes practicing without a doctor's supervision and prescribing narcotics such as morphine for pain.

VOA: standard.2010.05.14

It's very unlikely any of you would either but they go a long time without food, suggesting they do not want to cause this other chimpanzee pain.

你们也不会,但它们忍了很长时间才吃，这表明它们不想造成另一个黑猩猩受苦。

耶鲁公开课 - 心理学导论课程节选