A new study, published in the Proceedings of the National Academy of Sciences, found that happiness affects the human genome. The researchers concepts of happiness from a sense of purpose in life, and hedonic well-being, which focuses on the self-gratification. High levels of eudaemonic happiness were correlated with favorable gene expression for the immune system, including low inflammation and strong expression of antiviral and antibody genes. In contrast, high levels of hedonic happiness were correlated with high inflammation and weak expression of antibody and antiviral genes.

The researchers working on the study, Steven Cole and Barbara Fredrickson, have been conducting research on psychology and the human genome for the last decade. This study took blood samples from 80 healthy adults to evaluate gene expression. The researchers also asked questions to determine what types of happiness participants displayed, such as asking how often the person’s life had a sense of direction for eudaemonic happiness and asking questions about how the person feels that are focused only on themselves for hedonic happiness. They also asked questions that identified confounding negative psychological and behavioral factors, but found a relationship after adjusting for those factors.

The current study shows that happiness with meaning is linked with good health. Happiness without meaning is generally associated with shallow sources of pleasure, which can be easily satisfied without consideration for others. Happiness with meaning, in contrast, focuses on how the individual is contributing to society. It does not just mean helping others, but it means finding a purpose in life that is that person’s way to contribute.

As described in Happiness Genes, other scientists have considered intrinsic happiness as linked with genetics. These analyses have contended that a life with some form of spirituality unlocks genetic potential for long-lasting happiness, while extrinsic sources that focus on tangible things do not provide that.