The study found people living in Denmark had the longest form of the gene, and as a result were found to be among the happiest nations in the world
The French are often accused of being grumpy and dismissive.
But Britons and Americans are also hardwired to be miserable, scientists claim.
Despite stable governments and good economies, those living in the UK and US will never be as happy as people in other nations, because they are simply born more miserable.
They are genetically programmed to be less cheerful than the Danes, for example, who top the list of the happiest nation.
And scientists at the University of Warwick discovered it all comes down to a gene which regulates levels of the hormone serotonin in the brain.
Short forms of the gene inhibit levels of the hormone, which can invoke depression.
Meanwhile those with longer forms of the gene are more likely to be happier, as a result of higher levels of serotonin in the body.
Researchers discovered people from Denmark have the longest form of the gene, and as such topped the happiness chart.
But Professor Andrew Oswald said it could be worse, we could be French - the nation with one of the shortest forms of the gene, which may explain their reputation for being grumpy.
Annual tables of national happiness ratings, compiled by organisations across the world, tend to rank Denmark at the top, along with nations including Panama and Vietnam.
They use factors ranging from job satisfaction to economic progress, health, wealth and education standards, along with weather, war and political stability to judge nations.
Scandinavians do well as their health is good, they are educated to a high standard and they earn more. But warm weather countries can do well too.
Some wealthy Western countries fare less well because there are big divides between rich and poor or they have high unemployment rates or less job satisfaction for instance.
But according to Professor Oswald, many of these may still be miserable even if they are earning a fortune, basking in sunshine and living to 100.
His findings from 131 countries for the ESRC Festival of Social Sciences, found genetics to be the most important factor but not the only one.
Those who are either young or old tend to be happiest rather than those who are middle aged.
Those who are slim are happiest, with obesity levels in some developed countries making them less happy as nations.
And being married, in a job and well educated can also be a contributory factor.
Professor Oswald, said: 'Intriguingly, among the nations we studied, Denmark and the Netherlands appeared to have the lowest percentage of people with the short version of the serotonin gene.'
He added that many individual Americans were happy but they tended to be descended from immigrants who came from countries like Denmark in the first place.
He said: 'There was a direct correlation between the (US) individual's reported happiness, and the levels of happiness in the country their ancestors had come from.
'Our study revealed an unexplained correlation between the happiness today of some nations and the observed happiness of Americans whose ancestors came from these nations.'
法國(guó)人經(jīng)常被指脾氣暴躁、目中無(wú)人。
然而科學(xué)家稱,英國(guó)人和美國(guó)人天生就注定要比別人過(guò)得悲慘。
盡管英美政局穩(wěn)定、經(jīng)濟(jì)繁榮,然而這兩國(guó)國(guó)民卻絕不可能過(guò)得像其他國(guó)家的人民那樣幸福,怪只怪他們“命不好”。
基因決定他們天生就比其他人更容易不開心,比如名列最幸福國(guó)民榜單首位的丹麥人。
英國(guó)華威大學(xué)(University of Warwick)的學(xué)者研究發(fā)現(xiàn),這都是因?yàn)槿梭w內(nèi)有一種調(diào)節(jié)腦內(nèi)血清素水平的基因。
若這種基因較短,則其會(huì)抑制這種荷爾蒙的含量,使人心情陰郁。
同時(shí)這種基因較長(zhǎng)的人體內(nèi)的血清素水平則更高,從而更容易感覺到幸福。
研究者們發(fā)現(xiàn)丹麥人的這種基因最長(zhǎng),而丹麥人也是世界上最幸福的人。
但安德魯·奧斯瓦德(Andrew Oswald)教授表示,我們不是法國(guó)人已經(jīng)是不幸之萬(wàn)幸了——法國(guó)人的這種基因最短,他們出了名的脾氣暴躁大概也可以就此找到原因了。
由全球各大組織編制的年度國(guó)民幸福指數(shù)排行榜都把丹麥排在首位,隨后是巴拿馬、越南等國(guó)家。
他們?cè)谂琶麜r(shí)考量了一個(gè)國(guó)家的多個(gè)因素,如工作滿意度、經(jīng)濟(jì)發(fā)展、國(guó)民健康、財(cái)富和教育水平,以及氣候、戰(zhàn)爭(zhēng)、政局穩(wěn)定性等。
北歐人的排名很高,因?yàn)樗麄儑?guó)民身體健康,受教育水平高,薪水也高。氣候溫潤(rùn)的國(guó)家排名也不錯(cuò)。
然而一些富裕的西方國(guó)家就表現(xiàn)欠佳了,因?yàn)檫@些國(guó)家要么貧富懸殊,要么就失業(yè)率很高,或者工作滿意度很低。
而且奧斯瓦德教授表示,就算這里面的很多人能賺大錢,能悠閑地曬日光浴或者活到100歲,他們也未必就過(guò)得幸福。
他的這項(xiàng)研究共調(diào)研了131個(gè)國(guó)家,研究成果參加了ESRC(英國(guó)國(guó)家經(jīng)濟(jì)和社會(huì)研究委員會(huì))的社會(huì)科學(xué)活動(dòng)周。研究發(fā)現(xiàn),遺傳雖是決定幸福感的最重要因素,但并不是唯一一個(gè)。
青年人或老年人都可能是最幸福人群,但中年人就不太可能。
身材苗條的人幸福感最強(qiáng)烈,一些發(fā)達(dá)國(guó)家的幸福排名就因國(guó)民較高的肥胖水平而下降。
而已婚、有工作、受過(guò)高等教育等都可能是有利因素。
奧斯瓦德教授說(shuō):“有趣的是,在我們調(diào)研過(guò)的所有國(guó)家之中,丹麥和荷蘭國(guó)民中血清素相關(guān)基因較短的人群比例最低。”
他補(bǔ)充說(shuō)道,雖然許多美國(guó)人過(guò)得也很幸福,但他們的祖先可能是從丹麥這樣的國(guó)家移民過(guò)來(lái)的。
他說(shuō):“美國(guó)個(gè)人的幸福指數(shù),與他們祖先發(fā)源地的國(guó)家幸福水平呈正相關(guān)關(guān)系。
我們的研究顯示,當(dāng)今某些國(guó)家的國(guó)民幸福水平與祖先是從這些國(guó)家遷移過(guò)去的美國(guó)后代的幸福指數(shù)存在著一種無(wú)法解釋的聯(lián)系。”