“There isn’t time, so brief is life, for bickerings, apologies, heartburnings, callings to account. There is only time for loving, and but an instant, so to speak, for that.”
—Mark Twain

If you could invest now to make your future self as happy and healthy as possible, where would you focus? According to Harvard professor and psychiatrist Robert Waldinger, it’s not fame, money or hard work that promises happiness and good health. It’s relationships.

Since 1938, Harvard’s Study of Adult Development has tracked the lives of 724 men, gathering medical records, recording conversations with their wives and visiting their homes to track their work and home life. The men came from different backgrounds (some were at Harvard, others from inner-city Boston), and eventually the research included wives and children of the participants. This project is one of the longest and most complete studies of adult life ever conducted, a rare and revealing look into lifespans from adolescence to over the age of 90.

When the participants became quinquagenarians, it wasn’t cholesterol levels or income that helped predict their future health. It was the quality of their relationships. The clearest message gleaned from this study is that good relationships help keep us happier and healthier, and these are the key takeaways reported by Waldinger, the study’s current director:

1. Loneliness is toxic: Social connections are good for us. People who are more connected socially are happier and live longer. The opposite holds true for lonely people.
2. Quality, not quantity: It’s not the quantity of friends or whether someone is in a committed relationship. It’s the quality of the relationship that counts. High-conflict relationships are horrible for our health, and warm relationships are beneficial.
3. Benefits to overall well-being: Good relationships protect more than our physical health, they also stave off mental decline.

So if relationships are the key to happiness and health, what’s the key to good relationships? Emotional intelligence. Some marriages are lonely or filled with conflict. Some family feuds are never resolved. Some friendships become taxed beyond repair. This is why SIYLI’s programs are designed around components that increase empathy, kindness and compassion by offering training to improve emotional intelligence. Whether at work or at home, emotional intelligence is the foundation of quality relationships—which, as Harvard’s Study of Adult Development shows, is the key to happiness and health.