Their behaviour might sometimes appear boring but organised people live longer, says a study.

An international team has carried out the study and found people who are ambitious, organised and conscientious live longer than those who are impulsive, the latest edition of the 'Health Psychology' journal reported.

According to researchers, the study has suggested that psychological traits can be as important in predicting health as medical and social factors, and conscientious people can live up to four years longer.

Moreover, highly conscientious people are less likely to smoke or drink alcohol to excess, and live more stable and less stressful lives, it found.

"Not only do conscientious individuals have better health habits and less risk-taking, but they also (have) more stable jobs and marriages and may even have a biological predisposition toward good health," lead researcher Professor Howard Friedman was quoted by 'The Daily Telegraph' as saying.

To reach the conclusion, the researchers looked at the three facets of conscientiousness: Self-control, organization and industriousness in the study, involving 8,900 participants from the US, Canada, Japan, Germany, Norway and Sweden.

They found the second two were most closely linked to longevity. Other traits included thoroughness, reliability, deliberation, competence and dutifulness.

"There is some evidence that people can become more conscientious, especially as they enter stable jobs or good marriages. We think our findings can challenge people to think about their lives and what may result from actions they do.

"Even though conscientiousness cannot be changed in the short term, improvements can emerge over the long run as individuals enter responsible relationships, careers and associations," co-researcher Margaret Kern said.