While these certainly aren't guaranteed (please don’t cite us in your divorce petition), here are some things science says will make you less likely to get divorced.

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1. Quit Smoking

A study published in 2010 (PDF here) found that if only one partner smoked, it caused more marital problems than differing religions, different backgrounds, even different plans for having children.

Couples are an astonishing 76-95% more likely to get divorced if only one of them smokes. The amount increases when the wife is the partner with the habit. While couples who both smoke have it a bit better, a 1998 study found they are still 53% more likely than non-smoking couples to end their marriage.

2. Take Up Optometry

Analysis of census data from 2000 found some professions seem to be almost divorce-proof. As one might expect, religious workers and clergy had some of the lowest divorce rates, but there were some slightly less obvious professions in the bottom ten. These included optometrists, shuttle car drivers and transit police, with optometrists clocking in with a ridiculously low 4% chance of getting divorced. Other low risk professions included farming and nuclear engineers.

If you think your job as a massage therapist, animal trainer, or mathematician puts you in the clear, think again. You’re in the top ten most-likely-to-get-divorced jobs.

3. Share Chores

Proponents of traditional gender roles in marriage often point to the fact that divorce rates increased as more women went into the workforce. But a study from the London School of Economics recently found that the stress on a marriage due to the wife working is completely offset when husbands contribute more to housework, childcare, and shopping. In turn, those couples are more likely to stay together.

The study found that in households split along traditional gender lines, with the wife staying home and the husband contributing nothing to the housework, the divorce rate was slightly higher than when both partners worked and contributed roughly equally to the housework. When both had jobs and the husband made a “minimal contribution” to the housework, the risk of divorce almost doubled.

4. Live in a Blue State

You might expect divorce rates to be highest in states with more liberal residents, but you’d be wrong. Even though it was the solidly blue California that pioneered “no-fault” divorce in 1969, a 2009 census report revealed that residents of more conservative states are more likely to get divorced than their more liberal counterparts.

The Census Bureau explained some of the possible reasons behind the trend. One, in states in the South and West of America, residents tend to marry younger than those in the Northeast, which in turn more often leads to eventual marital discord. Two, these states also have a larger population of immigrants, and the loss of a supportive familial and social network can put a strain on many immigrant marriages, resulting in higher divorce rates.

5. Hang Out With People Who Aren’t Divorced

But surely living in a red state isn’t causing people to get divorced. It’s obviously those other factors that contribute to the larger numbers, right?

That’s true, but even just knowing people who are getting divorced makes you more likely to do so yourself. Studies on “social contagion” have shown that if you have a divorced sibling, you are 22% more likely to get divorced. But it isn’t just family members who affect us; divorces between friends and even friends of friends up your chances of ending your own marriage. Therefore living in a state with higher divorce rates, even if you waited until you were older to marry, still affects your chances of staying together.

6. Marry Someone You Met at School

Last year, the dating site eHarmony conducted the largest study ever into whether couples who met in certain places were more or less likely to get divorced. They looked at the expected number of divorces for couples who met at places like church, school, work, bars, and dating sites, and compared them to how many actual divorces occurred. While in most cases the number of actual divorces was almost exactly what was expected, the biggest difference was couples who met at school. According to this study at least, if you met your spouse in high school, college, or grad school, you are 41% less likely to get divorced than the statistics predict. The other major difference was couples who met in bars, who were 24% more likely to get divorced than expected.

7. Have Sons

A study of over 3 million couples found that having even one daughter increases a couple’s chances of divorce, while have sons lessens them. A first born daughter makes you 5% more likely to split up, while three girls increase it by 10%. A 2007 report stated that in any given year, 52,000 first born daughters under 12 years of age would still have an in-residence father if they had been born boys.

There are a variety of theories on this. One is that men are more invested in raising sons and are therefore more likely to stick around. Alternatively, women may be more willing to leave bad marriages if they have daughters, to avoid modeling them as acceptable for their girls. This second theory perhaps makes more sense since an estimated 73% of divorces are initiated by the wife.