Age gaps in relationships are often commented on and judged in a negative light.
It seems a strange thing to get involved in - love between consenting adults is nobody else's business to interfere with - but societal taboos die hard.
That it remains a topic for scientific study is testament to this prejudice.
A recent study, published in the Journal of Population Economicshas found that the 'best' age gap, in terms of marital satisfaction, is none whatsoever.
The research, which used household panel data from Australia, found that both men and women tended to be more satisfied with a younger spouse and more dissatisfied with an older spouse.
Professor Terra McKinnish, the study's co-author, said:
We find that men who are married to younger wives are the most satisfied, and men who are married to older wives are the least satisfied.
Women are also particularly dissatisfied when they’re married to older husbands and particularly satisfied if they’re married to younger husbands.
This gap disappears after the marriage has lasted between 6-10 years. Researchers also believe dissatisfaction can arise due to different responses to financial concerns
We looked at how couples respond to negative shocks and in particular, if they have a major bad economic shock or worsening of their household finances.
We find that when couples have a large age difference, that they tend to have a much larger decline in marital satisfaction when faced with an economic shock than couples that have a very small age difference.
With differing ages there are also more likely to be differing views to family issues and expenditure, which can become points of tension.
However, these are general trends and not shouldn't otherwise concern anyone who has found happiness with someone of a different age already.