While the long-term impacts of such a practice remain unknown, Sophie Scott, a neuroscientist at University College London, said that laughter has also been shown to reduce the stress hormones cortisol and adrenaline and increases the body’s uptake of the feel-good endorphins.
There also appear to be cognitive benefits. Watching a funny video was tied to improvements in short-term memory in older adults and increased their capacity to learn, research conducted by Dr. Gurinder Singh Bains of Loma Linda University found.
How my heart sings 