How do happy marriages stay happy? What traits help a marriage endure? It’s a great question to ask. Researchers have spent decades dissecting marriages to figure out what works to keep couples happy for the long haul. Some of the most important traits are that they think like a team, they accentuate the positive, they know how to manage stress, and they know how to manage conflict. While the answers may not sound extremely surprising, it’s the evolution of how a couple handles these things over time that really makes the difference.