Shy? You may be less happy. Surveys say so.

In its happy journey into becoming anthropology, epidemiology is increasingly tackling social issues like they are diseases and using surveys as verification. They have time now, since that whole malaria problem has been solved.  Dr. Catharine Gale, Reader in Epidemiology at the University of Southampton, and colleagues from the University of Edinburgh and University College London looked at survey results and concluded that young adults who are more outgoing or more emotionally stable are happier in later life than their more introverted or less emotionally stable peers.

They examined data on 4,583 people who are members of the National Survey for Health and Development, conducted by the Medical Research Council. All were born in 1946 and the scholars sought to determine the effects of neuroticism and extraversion at ages 16 and 26 years on mental wellbeing and life satisfaction at age 60 to 64 and explored the mediating roles of psychological and physical health.

Extroversion was assessed by questions about their sociability, energy, and activity orientation. Neuroticism was assessed by questions about their emotional stability, mood, and distractibility.

Decades later, when the participants were 60 to 64-years-old, 2,529 of them answered a series of questions measuring well-being and their level of satisfaction with life. They also reported on their mental and physical health. Their answers pointed to a distinct pattern. They found that personality dispositions by the time of early adulthood have an enduring influence on well-being decades later.

"Few studies have examined the long-term influence of personality traits in youth on happiness and life satisfaction later in life. We found that extroversion in youth had direct, positive effects on wellbeing and life satisfaction in later life. Neuroticism, in contrast, had a negative impact, largely because it tends to make people more susceptible to feelings of anxiety and depression and to physical health problems," said Gale.

Greater extroversion, as assessed in young adulthood, was directly associated with higher scores for well-being and for satisfaction with life. Neuroticism, in contrast, predicted poorer levels of wellbeing, but it did so indirectly. People higher in neuroticism as young adults were more susceptible to psychological distress later in life and to a lesser extent, poorer physical health.

Gale added: "Understanding what determines how happy people feel in later life is of particular interest because there is good evidence that happier people tend to live longer. In this study we found that levels of neuroticism and extraversion measured over 40 years earlier were strongly predictive of well-being and life satisfaction in older men and women. Personality in youth appears to have an enduring influence on happiness decades later."

Citation: Catharine R. Galea, Tom Booth, René Mõttus, Diana Kuh, Ian J Deary, Neuroticism and Extraversion in Youth Predict Mental Wellbeing and Life Satisfaction 40 Years Later, Journal of Research in Personality, http://dx.doi.org/10.1016/j.jrp.2013.06.005,