A recent research published by John F. Helliwell and Shawn Grover from the National Bureau of Economic Research in Canada suggests that there is a causal relationship between marriage and happiness, and the friendship between the partners explains it.
The authors used data from the British Household Panel Survey, the United Kingdom`s Annual Population, and the Gallup World Poll to analyze the link between well-being and marriage and found that for people who regard their partner as their best friend, the well-being effects of marriage are doubled, even when factors like age, gender, income, health, and pre-marriage life satisfaction are controlled.
"We do think it`s more about that social relationship than the legal status," Grover said. "Marriage, in a sense, is a super friendship,` he added.The authors state that the protective effect of marriage extends to even the 40s and 50s, a time people usually suffer from mid-life crisis and happiness is at its lowest level.
“We find that the married have a less deep U-shape in life satisfaction across age groups than do the unmarried, indicating that marriage may help ease the causes of the mid-life dip in life satisfaction and that the benefits of marriage are unlikely to be short-lived,” Helliwell and Grover concluded.