That is despite many people in the age group having at least one chronic disease.
Participants were asked to rate how confident, cheerful, relaxed and useful they felt in their early 60s and then again aged 68 to 69.
The Medical Research Council survey has tracked the health and wellbeing of 1,700 people since their birth.
When the responses of those aged 60 to 64 were compared to their feelings towards the end of their seventh decade, the survey found there was an overall average improvement in all aspects of wellbeing.
This mirrors the results of previous studies which found that people in their 60s and 70s were more content than those in their 50s.
And a recent large survey of UK adults found those aged 65 to 79 to be the happiest age group.
Those aged 45 to 59 reported the lowest levels of life satisfaction.
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Dr Mai Stafford, the programme leader at the MRC’s unit for lifelong health and ageing at University College London, said it (Free-Pr-Online.com) was not yet clear what was behind the rise in wellbeing during people’s 60s.
“We found that one in five experienced a substantial increase in wellbeing in later life, although we also found a smaller group who experienced a substantial decline,” she said.
“The benefit of using a cohort study like this is that we can look at how individuals change over time.
“We hope this will allow us to pinpoint which common experiences may be linked to an improvement in wellbeing in later life.”
In their 60s and 70s, people are more likely to prioritise social relationships and look after their mental health, she explained.
“By that time you’ve worked out what makes you feel better and what doesn’t.”
Although people are living longer, poor health in old age is still a concern.
Most survey participants reported having at least one common chronic disease such as arthritis, diabetes or hypertension.