Why some people choose to act altruistically is unclear, says lead study investigator Dharol Tankersley, a graduate student in Huettel's laboratory.

為什么一些人會選擇利他行為目前并不清楚。

I am not concerned here with the psychology of motives. I am not going to argue about whether people who behave altruistically are "really" doing it for secret or subconscious selfish motives.

這里我的旨趣不在動機的心理學方面，我不準備去論證人們在做出利他行為時，是否“真的”私下或下意識地抱有自私的動機。

But he found that systematically, no matter what, there's a significant number of people who do behave altruistically, no matter what.

但他發現，整體來看，無論如何，有大量的人會表現出利他的行為，無論如何。

The researchers also did brain scans of those who behaved most altruistically, before and after training.

在訓練前后，研究人員分別掃描了那些表現得最無私的受試者的大腦。

Debate is also intense over whether women should be paid for their milk or donate it altruistically.

對于女人是否應當出售人乳，抑或應當無私地捐贈出去，也存在激烈的爭論。

An unexpectedly large fraction of players acted altruistically to protect their weaker friends.

遠遠超出人們的預料,有很大一部分玩家在游戲中無私地保護那些弱者朋友.

Gymnosophists should do good, serves the needy masses altruistically, and then he can become a Buddha.

修行者要廣做善事，普渡眾生，才干成佛。