Dear Friends, I know it is a bit early to think about Thanksgiving, but it is November now, and a great time to not only consider travel plans and culinary recipes, but to take a moment to initiate the ritual of giving thanks. Long before scientists devised experiments to measure the health effects of gratitude, it seemed obvious that happiness is not something we acquire, nor is it bestowed on us. It’s a muscle to be exercised, a habit to be formed. In studies of adults and children — even...