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.

最新研究显示，与在家庭拍照时眉头紧锁的孩子相比，笑容最灿烂的孩子日后婚姻成功的机率要大三倍多。

根据科学家的此项研究，仅有5岁大的孩子随家人外出游玩时所拍的照片也能窥见这一未来趋势。

研究人员向近650位成年人索要了毕业那年拍摄的照片，并对他们笑容的深浅进行评级。

印地安那州迪堡大学的科学家还询问了这些年龄在21岁至87岁之间的受访者是否离异，继而将他们的回答与笑容等级进行对比。

研究人员称：“从受访者的笑容程度可以预见他们是否会在人生的某个阶段离婚。笑容越浅的人，日后越容易离婚。”

《动机与情感》期刊公布的此项调查结果显示，笑容最淡的人日后离婚的几率是其他人的三倍多。

另一项调查印证了上述结论，该调查还对仅有5岁大的孩子拍摄的照片进行了研究。

研究人员认为，越快乐的人越会想方设法克服恋爱和婚姻中的困难。

研究人员还认为，快乐型人士可能会寻找“阳光”型伴侣。