Happy are those ...

The field of positive psychology has great  insights into the happiness and the brain. Here is a very entertaining Ted talk  which is a good example.
An observation, and a question:

• Note the connection between the practices he mentions - gratitude, journaling, exercise, acts of kindness - and Christian spiritual disciplines. 
• What do you think is the basis for this positive outlook? As one who believes that God is redeeming and restoring the world, I have hope, and thus a basis for a positive outlook. Apart from that, I don't quite get what the basis might be for this positive outlook, other than that it works ... that is, those who cultivate positivity are indeed happier and more productive, as demonstrated in a great deal of recent research.