Whether Whitney Houston, who died on Saturday (Feb. 11), had substance abuse problems before her marriage to the singer Bobby Brown, or whether she was influenced by his “bad boy” ways, one thing is clear: the fact that the couple shared a drug habit is not surprising, experts say.

By and large, couples tend to have similar drinking, drug and smoking habits, research shows.

A common reason for this is that we tend to marry people who share our values and interests, including activities such as drinking and smoking, said Kenneth Leonard, director of the Research Institute on Addictions at University at Buffalo, in Buffalo, N.Y.

Are You Using AdSense? Google.com/DoubleClickTry Google’s Complementary Solution to Also Serve Your Other Ads.Hem Incense at low prices www.incensemania.comOver 70 exotic incense fragrances Free shipping on orders over $50Glass Vials & Bottles www.rapidlabs.co.ukVial, Bottle & Closure Supplier Small or Large Qty’s, Lowest PricesAds by Google

“Oftentimes, people will not be accepting of a partner who is doing something that is sort of different from themselves,” Leonard said. This means relationships in which one couple is a heavy smoker or drinker, and the other is not, often won’t last, or won’t begin in the first place, Leonard said.

In fact, one of Leonard’s studies showed that recently married couples who were discordant in their drug and alcohol use — that is, one was a heavy user and the other was not — were more likely to be unhappy in their marriage compared with those who shared these behaviors— for better or for worse.

And other research suggests older couples who are discordant in these behaviors are more likely to divorce, Leonard said.

But that doesn’t mean you should go looking for a mate that has similar alcohol and drug habits as you, Leonard said. What is more important in terms of a lasting relationship is that couples maintain similar values and expectations about the marriage, he said.

And while marrying your drinking buddy may mean that your marriage won’t suffer, the shared behaviors “may promote continued dangerous levels of drinking or drug use,” and possibly have a detrimental impact on other parts of your life, such as your ability to parent, Leonard said.