The paragraph is followed by an incomplete phrase or sentence which summarizes the main idea of the paragraph. Choose the missing words of the phrase or sentence. 

Are people less happy or more happy the older they get? If you answered more happy, then you were right based on a study in 2008. It found that people generally become happier and experience less worry after age fifty. In fact, it found that by the age of eighty-five, people are happier with their life than they were at eighteen.
The （） between age and happiness.