Children with the brightest smiles in family photographs are more than three times likely to have a successful marriage than those who frown, according to research.

According to scientists, even photos taken of family outings when the child is as young as five can show a glimpse of the future.

The researchers asked almost 650 adults for pictures taken during their final year school and rate the brightness of their smiles.

The scientists, from DePauw University in Indiana, also asked the volunteers, between 21 and 87, whether they had ever been divorced, and subsequently matched their answers with the data on their smiles.

"Smile intensity predicted whether or not participants divorced at some point in their lives," the researchers said, adding: "The less intensely participants smiled, the more likely they would be divorced later in life."

It found that those with the weakest smiles were more than three times as likely to have been through a divorce, according to the journal Motivation and Emotion.

A second experiment, which included pictures taken of people as young as five, backed up the conclusion.

The researchers believe that those who are generally happier are therefore more likely to try to work through difficulties in relationships and marriages.

They also believe that those who are happy types may marry companions who reflect their own sunny disposition.

最新研究顯示，與在家庭拍照時眉頭緊鎖的孩子相比，笑容最燦爛的孩子日后婚姻成功的機率要大三倍多。

根據科學家的此項研究，僅有5歲大的孩子隨家人外出游玩時所拍的照片也能窺見這一未來趨勢。

研究人員向近650位成年人索要了畢業那年拍攝的照片，并對他們笑容的深淺進行評級。

印地安那州迪堡大學的科學家還詢問了這些年齡在21歲至87歲之間的受訪者是否離異，繼而將他們的回答與笑容等級進行對比。

研究人員稱：“從受訪者的笑容程度可以預見他們是否會在人生的某個階段離婚。笑容越淺的人，日后越容易離婚。”

《動機與情感》期刊公布的此項調查結果顯示，笑容最淡的人日后離婚的幾率是其他人的三倍多。

另一項調查印證了上述結論，該調查還對僅有5歲大的孩子拍攝的照片進行了研究。

研究人員認為，越快樂的人越會想方設法克服戀愛和婚姻中的困難。

研究人員還認為，快樂型人士可能會尋找“陽光”型伴侶。