People who consider themselves to be frail are more likely to abandon activities which can keep them healthy in old age such as taking regular exercise.

But others with a more positive attitude can remain socially active, healthy and enjoy a greater quality of life despite having equal or greater levels of physical weakness, a study found.

Researchers from Exeter University interviewed 29 people aged 66 to 98, who had varying levels of physical health and some of whom lived independently while others were in care homes.

Participants were asked about their experience of ageing and frailty to determine how their attitude could affect their health and quality of life.

Most participants, even those in the worst physical shape, maintained that they were still in good condition, with one commenting: "If people think that they are old and frail, they will act like they are old and frail".

But in the two people who did consider themselves frail, researchers identified a "cycle of decline" where their outlook had led them to withdraw from socialising and exercise – even though they were physically stronger than some other participants.

Previous studies have shown that elderly people who are physically active and have a rich social life remain healthier and happier in old age.

Krystal Warmoth, a PhD student who led the study, presented her findings at the annual conference of the British Psychological Society last week.

She said: "It is almost a self-fulfilling prophecy.

"A person's beliefs about their self could lead to a loss of interest in participating in social and physical activities, poor health, stigmatisation, and reduced quality of life.

"You are as old as you feel and your own views of yourself, or taking on this identity of being frail, is not what you should be doing," she added. "You should try and keep positive about getting older and not assume you will be frail."