Altruism(1), one of the most difficult human behaviors to define, can be detected in brain scans, U.S. researchers reported on Sunday.

They found activity in a specific area of the brain could predict altruistic behavior -- and people's own reports of how selfish or giving they are.

"Although understanding the function of this brain region may not necessarily(2) identify what drives people like Mother Theresa, it may give clues(3) to the origins of important social behaviors like altruism," said Scott Huettel, a neuroscientist(4) at Duke University who led the study.

They set up an experiment in which they put 45 college students into a functional magnetic(5) resonance(6) imaging scanner, which can take real-time images of brain activity.

They gave the students various games to play, and told them that winning earned cash for either themselves or for a charity. The students had chosen the charities beforehand(7) from a list, the researchers report.

The students reacted differently depending on whether they won for themselves or for charity with the ones who described themselves as altruistic responding more strongly.

"The game involved reacting as fast as one can to the appearance of a target; if one responds fast enough, then money was earned," Huettel said.

The task was fairly simple, and the students did not give up any payments to themselves to give to the charities. But it cost enough effort that Huettel believes it did represent altruistic intent.

"Conversely, trying to watch people in their daily lives would make data collection nearly impossible. So, we settled on(8) self-reports as a good, albeit(9) imperfect, measure."

Huettel believes it is valid(10) to try to assess altruism scientifically.

"It is hardly the case that all altruistic acts come from people who are religiously faithful; there are undoubtedly many altruistic atheists(11)," He said.

"And, a religious explanation would have considerable(12) difficulty explaining why some animals help others of their species at significant cost or danger to themselves."

Next his team hopes to test children, and find out how and when altruism develops.

周日，美国研究人员称，最难解释的人类行为之一—利他主义可以通过脑部扫描探测。

他们发现脑部一块特殊区域的活动能预示利他主义行为—身体自己汇报自私度或者利他度。

本研究组长、杜克大学神经学家Scott Huettel说：“尽管对这部分脑功能的认识还无法解释到底是什么可以让人们像德兰修女一样，但却能让我们更加靠近诸如利他主义这样的重要社会行为的根源。”

研究人员将45位大学生送入能够实时记录脑部活动的功能磁共振成像扫描仪。

他们让学生们玩不同的游戏，并每次让他们选择赢的钱是留给自己还是捐献福利机构。游戏开始前学生们可以从列表上选择受捐赠的福利机构。

选择不同受益者，游戏结果大大不同，同时自称是利他主义者的学生的反应更为强烈。

Huettel说：“其中一个游戏是让学生目击突然出现的目标，如果反应够快就能赢钱。”

任务都很简单，学生们在此过程中不会有任何金钱损失。但是Huettel认为学生付出的努力足可以代表他们的利他意图。

“相反地，通过观察人们的日常生活搜集数据几乎是不可能的。所以，我们认为自我汇报是一种虽然不完美，但还不错的方法。”

Huettel认为这是评估利他主义的科学有效途径。

他说：“并非所有的利他行为都来自有宗教信仰的人；毫无疑问太多无神论者同样是利他主义者。”

“而且，宗教无法解释为什么有些动物会付出很大代价、冒很大风险帮助同类。”

下一步，他的团队希望测试儿童，试图发现利他主义行为是从何时、如何发展的。