altruism

志愿者无私帮助灾民的行为体现了真正的利他主义。

The volunteers' selfless help for the disaster victims showed true ___altruism.

这名亿万富翁匿名捐出全部艺术藏品的行为反映了一种甚至令他的家人都感到惊讶的默默利他主义。

The billionaire's anonymous donation of his entire art collection reflected a quiet ___altruism that surprised even his family.

神经科学家争论真正的利他主义是否存在，还是每一个帮助行为都为施助者带来了某种隐藏的好处。

Neuroscientists debate whether genuine ___altruism exists or if every helping act provides some hidden benefit to the helper.