Australia's top demographers are saying that women who marry men nine or ten years older or even one or two years younger than themselves do not have long married lives .
In fact, they have suggested that the secret to a lasting marriage is to marry a man who is about your own age, or if your parents are still together, marry a man whose parents are also still together.
Rebecca Kippen and Bruce Chapman, from the Australian National University, and Peng Yu, from the Department of Families, Housing Community Services and Indigenous Affairs, have traced the marital fortunes of 2482 Australian couples over six years to see what factors lead to compatibility, and what to divorce and separation.
They have advised that one should exchange vows with someone more or less like you.
However, surprisingly, similar education levels, attitudes to religion, and country of birth are not important when it comes to lasting matrimony.
In fact, age is the biggest factor in deciding if a couple stays together or not.
Marriages in which the husband was nine or more years older than the wife, or two or more years younger, had a separation rate of 17 per cent compared to about 10 per cent for their more age-compatible peers.
"Age captures a range of things about being in the same place in life, at the same time," News.com.au quoted Kippen as saying.
In addition, couples in which the husband's parents had divorced, but the wife's parents had not, were almost 90 per cent more likely to separate than pairs where both sets of parents were together.
It also helps if the husband is over 25 when one gets married, and if neither partner has children before getting married, because it is also important to have a similar attitude to wanting children or another child.
The data was drawn from the Household Income and Labour Dynamics in Australia, survey with an initial sample of 7682 households.
The findings will be presented at the HILDA conference in Melbourne next week.