Do you remember the 'I love to laugh' song from the film Mary Poppins? It was such a funny illustration that laughter and smiling are contagious! I've always thought it was a great analogy for how our energy vibrations are affected by either happy or sad emotions too. When we think happy thoughts, our vibrations are higher and a positive chemistry (endorphins) is released into our bodies. This is why we feel so healthy and talk about people 'glowing' when they are in love.
The opposite applies when we feel sadness or negative emotions; our vibrations are lower and if these emotions are suppressed the biochemistry released does not support optimum health.
Laughter therapy is recognised to be beneficial to good health.. what a great way to heal youself!