Sometimes, there’s a clear smoking gun leading to a divorce. One spouse catches the other cheating, getting drunk or high again after swearing it off, one spouse loses their shirt again at the gaming table, etc. But sometimes it’s a lot fuzzier than that, or just a combination of relatively minor things.

Below are some unlikely things that are anecdotally correlated with divorce (for reasons not always known):

1. Commutes over 45 minutes one-way
2. High incidence of divorce in a person’s family or social circle
3. Firstborn child is female, based on the US census
4. The wife developed a serious illness
5. The wife is a physician … who works long hours
6. The husband pitches in to help with half the housework
7. The wife drinks significantly more alcohol than the husband
8. The husband and wife maintain healthy body weights
9. One of the spouses is low in a hormone associated with affectionate nature

Read more in this Yahoo Health article by way of Prevention magazine: 9 Really Weird Causes Of Divorce .