Giovanni Maciocia has an interesting article on Joy as a cause of disease. One issue that I think he makes well into the article, is that we often define joy as a state of contentment or peace. I suspect as I was reading his article, that the way joy was defined was more of that hyper happiness that one sees in small children when they are over stimulated or over excited about company coming. It keeps one from sleeping and keeps one from thinking clearly about the present. Joy, in the way that I have come to define it is more a peaceful contentment.
I find the article fascinating and any commentary I have really underscores the need for cultural understanding when translating from one language to the next. Language may be the words we use, but the meaning is influenced by the culture. In order to communicate effectively, it is important to be certain to use words that as they are used within the culture.