Earlier this year, eminent marriage therapist John Gottman released a new book titled "The Science of Trust: Emotional Attunement for Couples." While you may not recognize Gottman by name, you may be aware of his work via Malcolm Gladwell's book "Blink." In that bestseller, readers were introduced to Gottman's knack for "thin-slicing" a couple based upon a few minutes of observation, and determining, with incredible accuracy, whether they would succeed or fail in their marriage. So what's the secret of relationship success? Based upon his work with couples, as well as statistical analysis, Gottman has determined that, "It's the balance between positive and negative emotional interactions in a marriage that determines its well-being - whether the good moments of mutual pleasure, passion, humor, support, kindness, and generosity outweigh the bad moments of complaining, criticism, anger, disgust, contempt, defensiveness, and coldness." Those couples that succeed in their marriages enjoy an overriding proportion of positive over negative sentiment. But how do you ensure that? "All couples, happy and unhappy, have conflict," writes Gottman, "but the ratio of positive to negative interactions during arguments is a critical factor." He has proposed that this ratio should, ideally, be 5 to 1. While it's impossible to go through life tallying positive versus negative interactions, it is possible to determine intuitively whether your relationship is generally in the positive, or tending more toward the negative. And then you can change it. I often advise couples to get in the "5 to 1 zone," and it's one of those pieces of simple advice that I often remind myself to practice in my own marriage. It isn't easy to maintain a surplus of positivity, but it is possible. In his latest book, Gottman encourages couples to cultivate emotional attunement through awareness, tolerance, understanding, non-defensive listening, and empathy. "Boiling down the richly complex body of work described in the book to one sentence, Gottman's point is that trust is made of people believing that their partners will be nice, that the partner will make an effort to make life better for you," writes sex educator Emily Nagoski in her intellectually vivacious blog, Sex Nerd. So there you have it - it all comes down to the "power of nice." While many men like to complain that nice guys often finish last, it would seem that couples that are nice to each other tend to last the longest. So why is it often so darn hard to be nice to our partners? Or why do we often end up being nice to everyone except the ones we hold closest? Why is nice so elusive? "Maybe you plain old don't know how to be nice. Maybe in your family of origin, people just weren't nice to each other, so you never learned that skill. Or maybe you didn't learn rules of Being Nice that are compatible with the rules your partner learned," writes Nagoski. "The hardest possibility is that you are your partner have been sucked into a dynamic of retaliation - you're like Israel and Palestine, where neither one can be the first NOT to retaliate." Gottman argues that it's hard to be emotionally attuned to your partner when you're stressed out, which so many of us are today. Stress hijacks our brains and makes it hard for us to feel anything other than anxious or panicked. Stress creates a state of emotional triage, one that pushes nice to the wayside. I've also found that many couples are used to operating in states of highs and lows - a sort of relationship manic-depression - but are unable to carve out a middle ground. But nice requires that in-between state. Nice takes time, patience, and effort. "When people are angry and hurt, they get into a different physiological state, with heightened awareness of potential threats and diminished capacity for empathy and creative problem solving," says Nagoski. "They stop seeing the positive and start attributing negative personality traits to their partner, to explain the problems in the relationship. In their minds, their partner develops a reputation as untrustworthy. Contempt builds. And the whole thing spirals." So are you being nice enough to your partner? Are you in the 5 to 1 zone? If not, maybe it is time to start counting interactions. A little "nice" goes a long way.