Turns out, being selfish can affect you more than just losing you a few friends. There are two types of happiness that result from either self gratification or having a purpose in life and these scientist have figured out the affects each have on your human genome.
“Researchers from UCLA’s Cousins Center for Psychoneuroimmunology and the University of North Carolina found that people who have high levels of what is known as eudaimonic well-being — the kind of happiness that comes from having a deep sense of purpose and meaning in life (think Mother Teresa) — showed very favorable gene-expression profiles in their immune cells. They had low levels of inflammatory gene expression and strong expression of antiviral and antibody genes.
However, people who had relatively high levels of hedonic well-being — the type of happiness that comes from consummatory self-gratification (think most celebrities) — actually showed just the opposite. They had an adverse expression profile involving high inflammation and low antiviral and antibody gene expression.”