Feelings of satisfaction with life are shaped more by people's personalities than by their circumstances, a study suggests.
Although factors such as social circles, income and health influence our levels of contentment, they are less significant than was previously thought, researchers say.
A team of experts adopted a fresh approach to address a long-standing psychological puzzle - how much feelings of fulfilment, rather than our experiences, reflect who we are.
Previous studies have failed to produce a clear answer because almost all have relied on people's self-ratings of their personality traits and life satisfaction, researchers say.
Self-ratings are often biased, by making unrelated things seem connected, or masking connections that actually exist - or both, the team says.
Joint study
The study was carried out by a team from the University of Edinburgh's School of Philosophy, Psychology and Language Sciences and the University of Tartu in Estonia.
The findings are published in the Journal of Personality and Social Psychology.
"It turns out people's life satisfaction is even more about their personality than we thought," says lead researcher Dr René Mõttus, of the University of Edinburgh.
"Personality tends to be stable, gradually shaped by a mix of thousands of experiences and genetic factors. So, the more satisfaction is about personality, the less it is expected to react to life's ebb and flow."
Combined sources
To overcome the limitations of previous studies, researchers combined two sources of information.
First, the team asked more than 20,000 people to rate their personality traits and life satisfaction. In addition, each participant was rated by someone else who knew them well.
By cross-referencing the two sources of information, researchers could identify where both agreed. This allowed them to estimate life satisfaction's links with a range of personality traits, free of conventional errors and biases.
They found that personality traits were more strongly related to life satisfaction than suggested by previous studies.
About 80 per cent of the differences in people's life satisfaction could be traced to their personalities - nearly double the estimates of previous studies.
Researchers sourced their data by surveying members of the Estonian Biobank - a collection of health information from volunteers across the country.
Emotional stability
"Broadly speaking, more satisfied people were more emotionally stable, extraverted and conscientious," said Dr Mõttus. "But more specifically, those satisfied with their life felt understood, excited and decisive, while less satisfied people felt envious, bored, used, unable, and unrewarded."
Study outcomes were the same for participants from a range of nationalities, showing that the findings were true across diverse groups of people.
The team also found that among a subset of participants tested a decade earlier, the associations appeared to last over time.
Even when satisfaction does go up or down, it tends to return to levels consistent with personality more broadly, the study concluded.
"This does not mean that experiences cannot have lasting influences on life satisfaction," explained Dr Mõttus. "But when experiences do matter, they have to shape people much more generally than simply making them more or less satisfied with life. This takes time and doesn't happen too often."
