A substantial survey carried out by Stack and Eshelman measuring marital status and happiness across 17 nations using a sample of 18,000 adults concluded that married couples were more likely to report being happy than those who cohabited.(Less,2007;Stack and Eshelman, "Marital Status and Happiness: A17-Nation Study.")
There are many resons offered for the claim of being more happiness between married couples compared to other couples. One of them claims that married people are generally healthier than unmarried people and those who are healthier are likely to be happier.(Wu et al,2003)
Other explanations include greater commitment levels within marriage, which in turn have an effect on people's perception that the relationship will last. Another consequence of the perception of greater commitment is that there tends to be lower levels of stress and higher levels of security among married couples, and, therefore,better psychological well-being.(Less,2007;Marcussen)
A further explanation is that the greater financial stabil ...