The two surveys involved around 370,000 people in the UK.

Being married brings people more lifelong happiness than being single, new research finds.

The boost to happiness in being married also persists into old age.

The positive effect of marriage is even stronger for those people who described their partner as their best friend.

The findings were just the same for those people who lived together but were not actually married.

Professor John Helliwell, study co-author, said:

“Even after years the married are still more satisfied.

This suggests a causal effect at all stages of the marriage, from pre-nuptial bliss to marriages of long-duration.”

The results come from two surveys that involved around 370,000 people in the UK.

The honeymoon phase was not the only time when marriage boosted happiness.

Typically, middle-aged people see a dip in their satisfaction with life.

However, Professor Helliwell said:

“Marriage may help ease the causes of a mid-life dip in life satisfaction and the benefits of marriage are unlikely to be short-lived.”

The social effects of being married appeared to be how it increases happiness.

Having a lifelong friend — indeed a ‘super-friend’ — helps explain why the positive effects of a partnership last so long.

Professor Helliwell said:

“The well-being benefits of marriage are much greater for those who also regard their spouse as their best friend.

These benefits are on average about twice as large for people whose spouse is also their best friend.”

The study was published in the Journal of Happiness Studies (Grover & Helliwell, 2017).