Pat

A sample of 222 undergraduates was screened for high happiness using multiple confirming assessment filters. We compared the upper 10% of consistently very happy people with average and very unhappy people. The very happy people were highly social, and had stronger romantic and other social relationships than less happy groups. They were more extraverted, more agreeable, and less neurotic, and scored lower on several psychopathology scales of the Minnesota Multiphasic Personality Inventory. Compared with the less happy groups, the happiest respondents did not exercise significantly more, participate in religious activities significantly more, or experience more objectively defined good events. No variable was sufficient for happiness, but good social relations were necessary. Members of the happiest group experienced positive, but not ecstatic, feelings most of the time, and they reported occasional negative moods. This suggests that very happy people do have a functioning emotion system that can react appropriately to life events.
VERY HAPPY PEOPLE
Ed Diener and Martin E.P.  Seligman
Very Happy People (pdf file)

This is a good description of my mom. I always called her a golden retriever because she was naturally cheerful.

My mom once said to me, in the middle of a conversation about the number of kids in our family who have significant problems (and after I had pointed out that optimism was her natural state): "It's true. I always think things are going to get better."

She paused, and thought for a moment.

Then said, "I don't know why," and we both laughed.

That was my mom. Someone needs to bottle the brain chemicals she had.