Older people live longer if they are happier, according to new research into the importance of emotional wellbeing.

A study of 3,800 people aged 52 to 79 found that those who rated their happiness the highest were significantly less likely to die in the following five years than those who were least content.

Even after taking into effect the impact of age, disease and lifestyle factors on people’s happiness, researchers found that the happiest group had a 35 per cent lower risk of death than the least happy.

Although the results do not prove whether happiness actually causes longer life, they back up previous research which links wellbeing and a positive outlook to longer life.

Prof Andrew Steptoe, who led the study, said: “The happiness could be a marker of some other aspect of people’s lives which is particularly important for health.

“For example, happiness is quite strongly linked to good social relationships, and maybe it is things like that that are accounting for the link between happiness and health.”

While previous studies have asked participants to rate their happiness over a specific time period – the past month, for example – the latest survey assessed people’s mood at four points on a particular day.

This reduced the risk that people’s memories of how happy they had been would differ from reality and confound the results, the team from University College, London said.

Happiness was measured using ecological momentary assessment (EMA), in which participants were asked to give themselves a mark from one to five in several categories.

Positive affect – the measure used to designate how happy they were overall – was taken as a combination of people’s self-reported scores for happiness, excitement and contentment.

Participants were also asked to assess their levels of worry, anxiety and fear, but after controlling for conditions such as depression the researchers found no connection between these negative feelings and a shorter lifespan.

Prof Steptoe explained: “On a five point scale you could feel four points happy and two points worried at the same time. It is not a single dimension you are looking at, it is much more complicated than that.”

Writing in the Proceedings of the National Academy of Sciences journal, the researchers reported that five years on from their assessment, just 3.6 per cent of the happiest participants – those who had the highest positive affect – had died.

In contrast, some 4.6 per cent of those who were averagely happy and 7.3 per cent of the group with the lowest positive affect had died during the same time frame.

After accounting for factors including depression, physical health and wealth, the researchers found that the happiest people were more than a third less likely to die.

Dr Ros Altmann, director general of Saga, said: “This study certainly fits in with our philosophy which is that if you want to have a happy and fulfilling life then you will benefit from it.

“We do believe that there is a definite connection between happiness and longevity and this is yet another study that upholds that link.”