Some people are born with the belief that they are masters of their own lives. Others feel they are at the mercy of fate.

New research shows that part of those feelings are in the genes.

Psychologists have long known that people confident in their ability to control their destinies are more likely to adjust well to growing old than those who feel that they drift on the currents of fate.

Two researchers who questioned hundreds of Swedish twins report that such confidence, or lark of it, is partly genetic and partly drawn from experience.

They also found that the belief in blind luck-a conviction that coincidence plays a big role in life is something learned in life and has nothing to do with heredity.

The research was conducted at the Karolinska Institute-better known as the body that annually awards the Nobel Prize for medicine by Nancy Pedersen of the Institute and Margaret Gatz, a professor of psychology at the University of Southern California in Los Angeles. Their results were recently published in the United States in the Journal of Gerontology.

People who are confident of their ability to control their lives have an "internal locus of control,"and have a better chance of being well adjusted in their old age, said Pedersen.

An "external locus of control," believing that outside forces determine the course of life, has been linked to depression in latter years, she said.

"We are trying to understand what makes people different. What makes some people age gracefully and others have a more difficult time?" she said.

The study showed that while people have an inborn predilection toward independence and self-confidence, about 70 percent of this personality trait is affected by a person's environment and lifetime experiences.

Pedersen's studies, with various collaborators, probe the aging process by comparing sets of twins, both identical and fraternal, many of whom were separated at an early age.

The subjects were drawn from a roster first compiled about 30 years ago registering all twins born in Sweden since 1886. The complete list, which was extended in 1971, has 95,000 sets of twins.

有些人天生相信他們是自我生命的主宰，其他人則覺得他們受到命運的支配。

一項新的研究發(fā)現(xiàn)這些感覺部份來自基因。

心理學家早就知道有信心掌握自己命運的人比那些覺得自己是受命運擺布的人更能適應老化。

兩位研究學家在詢問了好幾百對瑞典的雙胞胎后報告說，這種信心，或是信心的缺乏，一部份是與基因有關，另一部份則是來自經驗的累積。

他們同時發(fā)現(xiàn)，相信盲目運氣的人--認為巧合在生命中扮演一個很重要的角色--是在生活過程中學習而來的，與遺傳毫無關系。

這項研究是在卡洛林司卡機構里進行的。這個機構亦是每年頒贈諾貝爾醫(yī)學獎的團體。該研究是由此機構的南西?皮德森與洛杉磯南加大的心理學教授瑪格麗特?賈茲所主持，他們這項研究結果最近在美國老年學的期刊上登出。

皮德森說，對自己掌握生命的能力有信心的人有一種‘內在控制的基因位點’，比較能夠適應老年期。

她說，相信外在力量決定生命之旅的‘外在控制的基因位點’與晚年沮喪的情緒有關。

她說：‘我們想了解人與人之間相異的原因是什么。是什么原因使有些人安然悠哉地步入晚年，而有些人則比較困難?’

這項研究顯示，有人能夠擁有天生的自信與獨立，而百分之七十有這種個性的人，會受到環(huán)境與一生的經驗所影響。

皮德森的研究，囊括了許多不同的研究學者，從事雙胞胎的比較，并探討老化的過程。這些同卵及異卵雙胞胎有許多都在很小的時候就分開了。

研究對象是由一本三十年前編纂的名冊所抽出。這本名冊登記有自一八八六年以降，所有在瑞典出生的雙胞胎。這份完整的名單―直延續(xù)到一九七一年，共行幾萬五千對雙胞胎。