The Optimum Level of Well-Being: Can People Be Too Happy?
Perspectives on Psychological Science (2007) - Comment
pubmed: 26151972  doi: 10.1111/j.1745-6916.2007.00048.x  issn: 1745-6916  issn: 1745-6924 

Shigehiro Oishi, Ed Diener, Richard E. Lucas