If you have a friend who never buys a round or who rarely pays their fair share, try not to get too angry.

Because being mean could be in their genes. Scientists have pinpointed a stretch of DNA that makes people stingy with their cash.

Around one in four of us carries the 'mean gene', which we have inherited from our parents.

In the study, those with the gene gave less money to charity than others.

Such thrifty sorts may also constantly cadge cigarettes, rather than buying their own, or regularly borrow cash for bus fares, but rarely pay it back.

Keen to look out for themselves - and their cash - they may also insist on totting up every item of food they have eaten in a restaurant, rather than simply splitting the bill equally.

The German researchers took samples of cells from inside the mouths of 101 young men and women and tested them for a gene called COMT.

The gene, which comes in 'G' and 'A' versions, is known to influence brain chemistry and the researchers believed it may do so in a way that affects how generous - or not - we are towards others.

The volunteers were given a gambling computer game to play and then told they could donate some or all of their winnings to a poor child in Peru.

To tug the heart strings, they were shown a picture of a girl called Lina and a bracelet that she had knitted.

The type of COMT gene did not affect how much the men and women won on the gambling game - but it did affect how much they gave to charity.

More than 20 per cent of those with the 'G' version gave all the cash they had won to Lina, but fewer than 2 per cent with the 'A' version were as generous.

On average, those with the 'A' version, or the 'mean gene' gave less than half as much to charity, the University of Bonn study found. But tight wads can't entirely blame their DNA.

Previous research has shown that our propensity towards generosity is only partly explained by our genes.

This means that other factors, such as upbringing, education and religion also play a role.

Spendthrifts, however, don't necessarily have the moral high ground. It is thought that one of the reasons we splash our cash or help others is simply because it makes us feel good.

Writing in the journal Social Cognitive and Affective Neuroscience, the researcher said: 'Altruism is defined as a selfless concern for the welfare of others.

'However, there is a great debate in the literature if true altruism really exists.

'People who doubt the existence of pure altruism argue that helping others is intrinsically rewarding and therefore they are exercising their personal interest to benefit their own selves rather than others.'

相关中文:

如果你有一位朋友从来都不请客,甚至都很少愿意AA制,那么你也不必太生气,因为这很可能与他的基因有关系。据英国《每日邮报》11月4日报道,科学家终于找到了“吝啬基因”,这或许可以从遗传学角度解释小气鬼们为什么把钱包捂得这么严实。

德国波恩大学研究人员提取了101位年轻男性和女性嘴里的细胞样本,并在样本中检测一段名为COMT的基因。该基因分成G碱基和A碱基两种类型,其能够影响脑化学,进而有可能左右人们慷慨与否。

在实验中,志愿者被要求去玩一个赌博电脑游戏,然后告诉实验人员他们愿意将赢取的一部分还是全部奖金捐赠给秘鲁的贫困儿童。为了使实验任务更加真实,实验人员还给志愿者呈现了一个名叫莉娜的秘鲁贫困女孩的照片,以及一只由她编织的手镯。

实验结果表明,拥有G碱基的志愿者有超过20%的人将他们赢的所有钱都捐给了莉娜,但是拥有A碱基(即“吝啬基因”)的志愿者仅有不到2%的人能够像G型人这样慷慨。

通常,人类每4人中间大约就有1人携带有“吝啬基因”,他们表现得特别注重自己的钱财,比如时常讨要香烟而不是自己去买,或者定期借钱付公交车车票,但不怎么还钱。而且,那些携带“吝啬基因”的人比其他人捐赠给慈善机构的钱更少。

不过,吝啬的形成也不能完全归咎于基因。之前的研究已经表明,一个人慷慨与否只能部分地用基因来解释,诸如抚养、教育和宗教等其他因素也有不同程度的影响。

(来源中国日报网)