An 85-year-long Harvard study found that positive relationships are the single biggest contributor to happiness, with friendships playing a central role. According to the research, maintaining stable, long-term friendships is one of the seven habits associated with happier and healthier lives.
However, not all friendships serve the same purpose. As reported by CNBC, the ancient Greek philosopher Aristotle identified three distinct types of friendships, and Arthur Brooks, a Harvard professor who teaches a course on happiness, believes all three are essential for a fulfilling life.
