Ever wonder why some people are just bubblier than others? Happiness and positivity may just be written in their DNA.
While our outlook and emotions change based on our experiences and other environmental factors, positive affect is said to be up to 64% heritable.
In a 2017 study involving over 2500 African-American participants, two loci were found to be associated with differences in positive affect and well-being. These results stayed true even after accounting for other cofactors such as gender and childhood maltreatment.
For both loci, having the minor allele (the second most common version of the sequence at the locus) was associated with greater positive affect. In addition, one of the loci was also found to change expressions of some microRNAs (which are small pieces of RNA that may be playing a part in regulating gene expression). This is useful information because it gives us a clue about the mechanism by which having one variant predisposes a person to a more or less positive affect. For instance, one of these microRNAs has previously been found to influence the reward pathway, which, of course, mediates a person's happiness or contentment. In this way, this study provides insight on what is going on under the hood. To learn more, check out the details here: https://www.ncbi.nlm.nih.gov/pubmed/27595594
It is important to be mindful that the study's sample size is still quite small for a genome-wide association study and that there is still very little existing literature on the genetic factors that underpin positive affect. This investigation should be replicated using data from other populations. Nevertheless, the study is a great springboard for more research to come.
Find out on Genomelink today about your predisposed sense of happiness!