Now, in a paper titled Hope I Die Before I Get Old, Dr.Heather Lacey and her coauthors study happiness in people between 21 and 40, and in people over sixty.

• 现在，在一份题为希望我死在我变老，希瑟莱西博士和她仔细研究幸福的人21和40之间，并在超过60人。