My niece, Maria, is about 9 months old. She is a happy child most of the time. I guess this happens because she feels the care and love of her parents and also of people around her.
All the times I see her, she is very found of her parents and my mother (her grandmother) and she reacts accordingly: she laughs a lot, "speaks" and dance.
Here she is, as I see her most of the times: