Oxford University researchers found maintaining friendships requires more brain power. Their study concluded that people with real friends have to use more cognitive skills to understand what someone else thought.

　　英國牛津大學研究者發現維系友誼需要腦力。他們的研究結果表明，那些擁有真朋友的人必須要有更多認知能力，來了解別人究竟在想什么。

　　Scientists discovered a link between the number of friends people had and the size of their orbital prefrontal cortex, which is a region of the brain found just above the eyes.

　　科學家發現了擁有朋友數量和前額葉皮質部位大小有關系，該部位位于眼睛上方。

　　The conclusions, published in the journal Proceedings of the Royal Society B, shows for the first time that competency in social skills is determined by the size of peoples' brains.

　　英國《皇家學會生物學分會學報》刊登了這一結果，這一研究也是首次指出社交技能是由人們的大腦大小所決定的。

　　"We found that individuals who had more friends did better on mentalising tasks and had more neural volume in the orbital frontal cortex, the part of the forebrain immediately above the eyes," said Prof Robin Dunbar, who led the study.

　　我們發現那些朋友更多的人可以更好的完成腦力工作，前額葉皮質部位也更大，就是正好在眼睛上方的部位。“ 研究負責人的羅賓·鄧巴教授說。

　　"Understanding this link between an individual's brain size and the number of friends they have helps us understand the mechanisms that have led to humans developing bigger brains than other primate species."

　　"明白這種大腦體積與朋友數量之間的關聯，有助我們理解使人類大腦比其他靈長類動物進化得更大的機制。"

　　"The frontal lobes of the brain, in particular, have enlarged dramatically in humans over the last half million years."He added: "Of course, the amount of spare time for socialising, geography, personality and gender all influence friendship size, but we also know that at least some of these factors, notably gender, also correlate with mentalising skills."

　　“腦部的前額葉部分，特別是在過去的50年里有著顯著增大。” 他還補充道：“當然，參與社交活動的閑暇時間、地域、個性和性別都影響朋友數量，但我們也知道，其中有部分因素， 尤其是性別，與心智化能力相互影響。”

　　"Our study finds there is a link between the ability to read how other people think and social network size."

　　"我們研究還發現看懂別人的想法和社會網絡規模之間也有一定的關系。"

　　Tests were conducted on 40 people, with scientists taking anatomical Mr images of their brains to measure the size of their prefrontal cortex, which is used for high-level thinking. They were all volunteer postgraduate students of "broadly similar ages with potentially similar opportunities for social activities".

　　40名志愿者加入了研究過程，科學家借助核磁共振成像技術測量參與者前額葉皮質部位大小，前額葉皮質部位通常用于深層次的思考。研究中的志愿者都是研究生，年齡相仿，參與社交活動的機會相當。

　　Participants were asked to make a list of people they had social – rather than professional – contact with over a seven day period. They also took a test to determine how competent they were at 'mentalising', which is the capacity to understand what another person is thinking, a crucial aspect in how people handle the social world.

　　研究人員要求志愿者列出最近7天內聯系的人員名單。這種聯系純屬社會交往，不包括工作層面的交流。 研究人員又測試志愿者的“心智能力”。這是一種理解他人所思所想的能力，在人們社交活動中起著重要作用。

　　Dr Joanne Powell, from the University of Liverpool, added: "Perhaps the most important finding of our study is that we have been able to show that the relationship between brain size and social network size is mediated by mentalising skills. What this tells us is that the size of your brain determines your social skills, and it is these that allow you have many friends."

　　利物浦大學Joanne Powell補充說，“也許研究中最重要的發現就是我們已經能夠證明大腦的大小與社會網絡規模之間的關系是由心智能力在起作用。這些也告訴我們你大腦的大小決定了你的社會技能，也就是這些決定了你能夠有多少個朋友。”