A new study is reshaping how people think about happiness, suggesting that the experiences people have during childhood can have a lasting effect on their happiness as adults. According to Insee, a French government statistics agency, the overall level of life satisfaction among the French population is 7.2 out of 10. However, only 12% of the French say they are completely happy, as found in a 2025 study by BetterHelp, an online mental health service. Research published in 2014 in The Economic Journal found that between 30% and 45% of a person's life satisfaction in adulthood is fixed, meaning it doesn't change much over time. Of that fixed component, 15% can be explained by the conditions and experiences of a person's childhood. More recent research from 2025 supports this idea, showing that children who grow up in environments with parental conflict tend to have lower life satisfaction later in life. In contrast, those who have warm and close relationships with their parents are more likely to experience greater happiness as adults. While factors such as financial stability, marriage, and health can influence happiness, the study suggests that family relationships, particularly the relationship between parents and children, play a major role in shaping a person's happiness throughout their life. The largest study on happiness ever conducted, carried out by Harvard University over nearly 85 years, also supports this view. The research, known as the Harvard Study of Adult Development, found that the key to a happy and fulfilling life lies in maintaining quality relationships. Dr. Robert Waldinger, a psychiatrist and director of the Harvard study, emphasized the dangers of loneliness, comparing its impact to that of tobacco or alcoholism. He noted that the relationships people have and the happiness they derive from them significantly influence their health. Maintaining strong, positive relationships, he said, is a crucial part of personal well-being.