Some say long married couples come to look like each other.
True or not, some medical studies now find that partners do mirror each other in one significant way -- how healthy they are.
Chris and Sue Stefans of Chicago are a good example. When they met through a dating service, they both had one firm requirement: They wanted to be matched with a smoker. And then three years into the marriage, Chris had what he thinks may have been a mid-life crisis. He decided they both had to quit smoking -- effective immediately.
Chris Stefans said it was, "just the fact that we want to be around as long as possible, and smoking is not the way to accomplish this." Stefans added that he remembered telling his wife, "We gotta do this now, and whatever it takes to do that we'll try."
They joined a stop smoking program, took a deep breath and threw away the cigarettes -- and were miserable.
In fact, Sue Stefans said she remembers going into it, "really not wanting to do it -- just kind of going along (with it)."
But despite her initial reluctance, they started exchanging almost hourly phone calls to encourage each other. The couple began to talk about the special vacations they might take with the money saved from not buying cigarettes. They also both described a healthy competition to see who could stick it out the longest, as well as a desire to stay smoke free for the other person.
"I think you don't want to let down your partner," Sue Stefans said.
It all worked. Five years later, the two smokers -- who started as teenagers -- now say they find cigarette smoke irritating. Their success, say researchers, may have something to do with the fact that they quit smoking together.
Duke University study found that smokers are five times more likely to quit if their spouses quit first. That's also true for other health behaviors -- you're five times more likely to stop drinking alcohol if your spouse stops drinking, and six times more likely to get a flu shot if your spouse gets one. And there are smaller, but still significant increases in other important habits. If your spouse begins first, you are also more likely to exercise, and to get screened for your cholesterol levels.
Northwestern Memorial hospital psychologist Greg Peterson says that's because people not only encourage each other, they become role models for each other.
"If I'm around people who are saying 'I'm on board with you,' 'I think it's great,' and 'Let me know how I can support you,' it's a lot better than, 'Are you sure you want to do that?' or 'Wow, that sounds hard'" Peterson said.
Peterson added along with that, if someone close to you successfully makes a change, you begin to believe that you can make that change too.
It's not willpower, said Peterson, but instead it was about "setting up environments that facilitate success."
And with one success under their belt, the Stefans say they're a littlle more confident about the next goal they share together, which is to lose weight.