The latest Household, Income and Labour Dynamics in Australia survey compiles responses from 12 waves of participants who were asked to rank their relationship satisfaction and factors leading to separation.

It gives us unique and intriguing insights into which couples last, why others break up and what is making men and women happy or unhappy. It can also help with match-making, with some fascinating statistics into what types of personalities are most compatible. The data is based on nearly 31,000 observations for each gender.

For example, men do not like it when their wives or girlfriends are more adventurous than them. And non-smokers do not like being with smokers.

The details of the HILDA survey allow us to paint a picture of who would be the most and least satisfied partners:

Overall, on a scale of zero to 10, married men in 2012 rated their relationship 8.5 and married women give it an 8.2. For de facto couples the ratings are slightly higher, at 8.6 and 8.3, respectively. These numbers are slightly lower than survey results in 2001.

We also learn that de facto couples are just as happy as married couples for the first few years but become less satisfied the longer they stay together without getting married. De facto couples are more likely to separate in the long term. 

We also learn the single biggest hazard contributing towards divorce or a breakup is being the victim of physical violence.

A marriage is six times more likely to break down if a husband beats his wife, according to the survey results.

There are lots of small, niggling things that put stresses on relationships such as the number of years you have been together, mental and physical health, whether you have dependent children, differences in age and education, and religious differences.

But, according to the results provided by 3167 married couples and 1207 de facto couples, beating your partner is more likely to destroy and end your relationship than anything else.

De facto v marriage survival

While de facto couples may rate their relationship higher, they are more likely to split up than married couples. About 90 per cent of married couples are still together after four years, compared to 74 per cent of de facto couples. After 11 years, about 80 per cent of married couples are still together, while just over half the de facto couples, 57 per cent, were still together.

Causes of separation

The single biggest contributing factor towards separation is physical violence against the other partner, predominantly against married women. The next-biggest contributor is poor mental health. So while friends and advice columnists might say your marriage failed because you put on weight or forgot why you fell in love, it turns out what really happened is that either you or your partner forgot to look after your mental health. Well, actually, it is probably the bloke, with poor male mental health more likely to contribute towards separation than if the woman is struggling. And de facto couples were more likely to separate because of poor mental health than married couples. In a nutshell, if men want their relationships to last, they should pay closer attention to their stress, anxiety and depression levels and do something about it.

More causes of separation

Other factors contributing towards divorce among married couples include: having children; age gaps of more than five years, particularly when the wife is older; financial troubles; one partner smoking; and the wife having a higher level of education. For de facto couples, issues leading to separation include: one person having stronger religious views than the other; large age gaps; and having children. Strangely, a major financial windfall was also likely to make a de facto couple separate, but not a married one. However, this was a rare occurrence and not considered statistically significant.

Most women are unsatisfied 

This round of HILDA surveys has given us a genuine voyeuristic experience. It asked more than 30,800 men and 30,900 women how satisfied they were with their relationships. It found, quite sadly, that most Australian women are unsatisfied within their relationships as the years go by. Fortunately, it gives some hints as to why.

Married women and women in de facto relationships are equally unhappy for the first 10 years. But women who have been with the same bloke for more than 10 years and never got married are particularly unsatisfied. In rating their relationship out of 10, they took .85 of a point off. Their boyfriends are also less happy than the men who married their girlfriends. And it gets even worse. After 20 years together, the de factos report very high levels of dissatisfaction compared to their first three years together, taking nearly a full point off their satisfaction levels.

While married couples become less satisfied with their marriage as the years go by, things get better when they hit the 20-year anniversary.

Both men and women report similar levels of relationship satisfaction after 20 years as the first six years of their marriage. Married men in their 60s are practically blissful.

The worst age to be a woman

Overall, women are much less satisfied with their relationships than their husbands and boyfriends are. The worst ages for women are during their 40s and 50s, when compared to satisfaction of women aged 18-29. Men also reported dissatisfaction during their 40s and 50s, but as much lower levels than women. But hang in there, sisters, things start to feel better after you reach 60. At least a little better, but never as good as the men. The only thing that helps improve satisfaction levels for women is having a partner at least five years younger than them.

Having a job doesn't make it any better

Women who work, full-time,or part-time, or are looking for work reported being less satisfied with their relationship than women who do not work.  However, women who do work found working 50 hours or more a week improved their relationship slightly.  

Men don't like their partners to be adventurous

Both men and women, but particularly men, do not like it if their partner is too adventurous, perhaps fearing they may cheat. We know this because the survey guessed at people's personalities based on whether they said certain traits applied to them or not. It found that Australians have much better relationships if they and their partner are both agreeable, conscientious, emotionally stable people. No surprises there.

The survey also found that when couples had different levels of agreeableness, the woman's satisfaction increases as she becomes more disagreeable, while the man's satisfaction decreases. Sounds like demanding women enjoy their relationships more. But women become less happy as emotional stability decreases, but it does not seem to bother men.

Opposites can attract

The survey found that extroversion has the least impact on the success of a relationship. So if you are an introvert and fancy an extrovert – go for it!  It is not a recipe for disaster as long as you have similar levels of adventurism, emotional stability and conscientiousness. In fact, an introverted man with an emotionally stable woman would be quite satisfied.  

Children are a risk factor

Having dependent children decreases relationship satisfaction for both men and women by at least 0.3 points out of 10. 

A big difference in education is a problem

Australians who did not finish high school become unhappy if their partner has a higher level of education than them. Women were particularly less satisfied if their partners had a university degree and they had not finished high school. While men who did not finish high school were mildly annoyed with university-educated partners, they really didn't like it when their partners had some other kind of post-school qualification.

Smokers and drinkers

There is clear evidence that non-smokers do not like it when their partner smokes. This is perfectly rational when you consider smoking smells, it is expensive, the non-smoker gets left alone at the restaurant table, and their partner is indulging in something with proven links to premature death. Non-smoking men dislike it more when their wives and girlfriends smoke than vice versa. However, there were no similar levels of dissatisfaction reported when one partner regularly drinks alcohol and the other doesn't.

Women are marrying older

The survey looked at the age at which people are shacking up with a partner and found the peak ages are from 25 to 29. There is evidence that people are partnering later and getting married later compared to the start of this century. While women were previously partnering mostly in their 20s, this is now happening just as much in their mid-30s.   

Lonely older women

The people most unlikely to find a partner and settle into a new long-term relationship are women aged over 50, with only 7 per cent moving in with a partner. However, this is not the case for older men, with about 12 per cent of men aged over 50 still meeting and moving in new partners. These men are presumably falling in love women under 50, hence the discrepancy in genders.