基因决定友谊 好友缘分是天注定？

Research has shown that people tend to become friends with people similar to themselves. But now friendship is in our genes, scientists believe, with two friends sharing the some of the same DNA, while in other cases, friends have different versions of the same gene。

To find out if that theory holds water, James Fowler, a professor of medical genetics at the University of California and his colleague Nicholas Christakis at the Havard University culled data from two large studies which collected genetic information as well as data on friendship, marriage and other relationships. Then they tested the friendship pairs from the studies for six genes known to influence human behavior。

Of the six genes tested, the first involved a gene called DRD2 which affects how much pleasure we get from alcohol and cigarettes and other addictive substances. The study revealed that people with a version of the gene tend to befriend others with the same version. The opposite relationship was found for a gene called CYP2A6. Those with a version of the gene linked to having an "open" personality, gravitated to people with a different version of the gene, according to the Harvard University。

Christakis said that reasons for us being drawn to those who are genetically similar to ourselves include us being thrown together with people with similar interests in sports clubs or at university. But we may also actively seek out those who are like us – even if we are unaware of the underlying genetics. For instance, thin people may stick together, unaware that each member of the group lacks genes that make it easy for others to pile on the pounds. In terms of opposite attracting, we may hunt out people whose personalities complement our own. Extraverts may meet their quieter pals through work。曾有研究表明这世界确实是“物以类聚，人以群分”。而如今科学家们有了新看法，那就是基因影响了我们的择友方式，一般来说，两个好朋友有一部分相同的基因，而在另外一些情况中，两个朋友之间也可能具备同一基因的不同类型。

为了验证该看法是否可靠，加州大学医学遗传学教授詹姆斯•福勒和美国哈佛大学教授尼古拉斯•克里斯塔吉斯从为美国两个大型研究所收集的关于友情、婚姻、以及其他关系的基因数据中进行了拣选。随后在每对好友身上对与人类行为相关的6种基因进行了研究。

研究发现，6种基因中，首先发现的名为DRD2的基因与人们从酒精和烟草及其他成瘾物质中所能获得的快感有着密切联系。携带该基因的人倾向于与同样带有此类型基因的人为友。而另一种名为CYP2A6的基因则为“互补好友”找到了答案。哈佛大学的研究表明，携带有此种基因与“开放”式性格特点有关的人，往往会被具备此种基因的另一构型的人吸引。

克里斯塔吉斯教授表示，人们倾向于与具备相近基因的人为友，也可以解释为什么体育俱乐部或者大学里兴趣相投的人们会扎堆在一起。但即使不知道潜在的基因作用，我们也会主动寻找与自己相近的人。比如，体型清瘦的人往往会粘在一起，但他们并不会意识到他们自身都没有容易让自己长胖的那种基因。而就“互补好友”而言，我们可能会去寻找那些能和我们个性互补的人们做朋友。生性好动者在工作中易于与好静者结成伙伴。