With graduation fast approaching and our days of care-free living slipping away, many of us have pondered the age-old question, “What makes us happy?”

Contrary to what we’ve been led to believe, it is not the result of following a set formula guaranteeing happiness. It is not a byproduct of achieving fame, fortune or a hand in marriage, nor is it freedom from struggle, at least according to Harvard psychiatrist Dr. George Vaillant.

Vaillant was so intrigued by the secret behind happiness that he sought to find its answer through monitoring contentment levels among 268 students from the Harvard graduating classes of ’42-’44 for more than seven decades in his comprehensive research titled “The Grant Study.”

“[We] measured them from every conceivable angle and with every available scientific tool,” Vaillant said.

To measure happiness, Vaillant categorized all possible responses under four varying levels of efficacy. The unhealthiest of responses he referred to as “psychotic adaptations,” which are found in the mentally ill and are characterized by paranoia and hallucination as the unconscious mind’s attempt to “create a reality tolerable for them,” Vaillant said. The next highest up, “immature adaptations” are responses such as passive aggression, projection and acting out. Socially normal people employed “neurotic defenses,” which, according to Vaillant, include “intellectualization, repression and dissociation.”

The “healthiest adaptations” turned out not to be defenses but abilities to turn undesirable circumstances into beneficial ones. Such strategies were common in “anticipation, humor and altruism.” It’s these qualities that form the foundation of the most rewarding personalities.

What separated those who viewed themselves as truly happy from those who did not was not in the events that made up their lives — it was in how they responded to those events. The key difference between the happy person and the unhappy one was that one viewed themselves as a victim to their circumstances, while the other sought ways to use it to their advantage. The degree to which happiness was attained was in the adaptations the participants employed to deal with and shape their reality.

Vaillant also identified “education, stable marriage, not smoking, not abusing alcohol, healthy weight and exercise” as the six major factors that lead to healthy and happy aging.

According to Vaillant, exercise plays a major role in regulating contentment as we age, important not only physically but mentally as well.

“Regular exercise in college predicted late-life mental health better than it did physical health,” Vaillant said. “Of the men diagnosed with depression by age 50, more than 70 percent had died or were chronically ill by 63.”

Yet of all these factors that influence lasting happiness, there was none quite as indispensable as the “power of relationships.” Underlying the foundation of relationships is perhaps the most valuable and most human adaptation: altruism.

Our desire to advance those around us without the expectation of anything in return provides us with a happiness rooted in unselfish adaptation. It is through altruism that we are enabled to extend our legacy beyond ourselves and make the outcomes of our efforts limitless. Although it requires vulnerability, it also promotes similar altruistic happiness within those you associate with.

According to Vaillant, contentment arises from taking risks to form deep relationships with others over superficial ones that prevent us from getting hurt.

“Positive emotions make us more vulnerable than negative ones. One reason is that they are future-oriented. Fear and sadness have immediate payoffs — protecting us from attack or attracting resources at times of distress,” Vaillant said. “Gratitude and joy, over time, will yield better health and deeper connections, but in the short-term actually put us at risk. That’s because while negative emotions tend to be insulating, positive emotions expose us to the common elements of rejection and heartbreak.”