Unlocking the Secret to Happiness: New Research Suggests Genetic Roots in Our DNA

Happiness — it’s something we all chase, yet for many, it can feel mysterious. While it's well known that life circumstances, relationships, and mental health have a profound effect on our well-being, could it be that our genes also have a hand in how happy we are?

A recent study led by Joey Ward and colleagues at the University of Glasgow suggests that the answer is yes, offering new insights into the biology behind happiness. Their research, published in Scientific Reports, investigates how genetics influences happiness across different ages and ancestral backgrounds.

Study Overview

The study used data from three significant cohorts to explore the effects of genetic predispositions for happiness:

• The Adolescent Brain Cognitive Development (ABCD) cohort (children aged 9–11)
• The National Longitudinal Study of Adolescent to Adult Health (Add Health) cohort (adults aged 25–35)
• The UK Biobank cohort (middle to older adults aged 45–83)

Researchers used data obtained from genome-wide association studies (GWAS) to determine polygenic scores (PGS) — numerical values that estimate an individual's genetic predisposition to a trait or condition — of happiness. In GWAS, the genome of a large cohort of people is studied to identify small variations in the DNA known as single nucleotide polymorphisms (SNPs). Scientists can then pinpoint specific SNPs that occur more frequently with certain diseases or traits.

In this study, researchers first scoured the genomes of 1,000 individuals in the cohort who had completed surveys indicating their levels of happiness. Using GWAS data obtained from saliva samples of this subsection of participants, known as the training set, the group established a PGS of happiness. They then validated the robustness of this genetic happiness score by assessing the remaining individuals of the cohort, known as the validation set, and comparing their determined PGS to their self-reported happiness levels. 

Could Your DNA Hold the Key to Lasting Happiness?

The study found that genetic predispositions for happiness had a constant influence on well-being across different life phases, independent of age or ancestry. In the ABCD cohort of children aged 9–11, those with higher genetic loading for happiness scores showed greater calmness, confidence, and energy. The researchers measured these traits through surveys and questionnaires, comparing them to each participant's polygenic scores to identify genetic links.

In the Add Health cohort (ages 25–35), similar self-reported well-being measures were collected, focusing on subjective happiness and emotional states. In this cohort, the researchers found a significant connection between genetic predispositions for happiness and subjective well-being, but this was only observed in participants of European ancestry.

In childhood (ABCD cohort), genetics had a stronger impact on traits like confidence and calmness, but as individuals age, environmental factors, life experiences, and cultural context play a larger role in shaping well-being, reducing the observable genetic influence.

Can Happiness Be Mapped in the Brain?

A unique aspect of the study was its investigation of the relationship between happiness-related genetics and brain structure. In the UK Biobank cohort of middle-aged and older adults (aged 45–83), individuals with higher genetic happiness scores showed larger volumes in specific brain regions, including white matter and the right hippocampus. Although no regions were significantly associated with happiness PGS after corrections, nominal associations were observed in white matter and the hippocampus tail.

The study builds on prior research linking key brain areas — such as the nucleus accumbens, frontal lobe, and hippocampus — to emotional regulation, demonstrating consistent connections between genetic predispositions for happiness and the structural characteristics of these regions. Strong relationships were also found between genetic happiness scores and the volumes of white and grey matter in the frontal lobes, underscoring the role of genetics in emotional well-being.

A Step Toward Understanding the Biology of Happiness

While this study offers valuable insights into the genetics of happiness, there are several limitations to consider. The UK Biobank does not fully represent the general UK population, as its participants tend to be healthier and have higher socioeconomic status, which may lead to a different distribution of happiness levels compared to the broader UK population. This bias is even more pronounced in the MRI sample, where participants skewed toward being fitter and healthier.

A similar limitation exists in PGS analysis, where the genome's linkage disequilibrium (LD) structure was based on individuals of European ancestry due to a small number of non-European participants in these cohorts. As a result, the findings may understate the impacts of non-European ancestries.

In conclusion, the study provides evidence that genetics influence happiness across age groups and ancestries. Genetic predispositions influence well-being in childhood and young adulthood and are associated with brain anatomy in older persons. Future research can build on these findings, considering both hereditary and environmental influences, to improve well-being and mental health.