This is a research oriented book focusing on strategies we can take to develop more happiness in our lives. It asserts that we have a "happiness set point" just like a weight set point. I think I may have hit mine as I don't seem to be budging past it, but I could be trying harder which I 'm working on. The author Sonja Lyumbomirsky is a a professor at the University of California at Riveside and is one of an impressive handful or researchers focused on positive psychology. This trend looks at what we can do to increase happiness rather then look at the pathological aspects of depression, which of course is important research too. Here is a useful link about positive psychology.
In addition to this set point, the theory asserts that our life circumstances account for only 10% of our happiness and that we have control over the remaining 40%. The book focuses on strategies to maximize that 40%. So far I'm finding it useful and helpful.
I'll report more when I've read more.
Make it a great day!