Why are some people happier than others? It is likely a major factor is genetic. Happiness genes have been found for the first time. In a study of 298,000 people.
The researchers found three genetic variants for happiness, two variants that can account for differences in symptoms of depression, and eleven locations on the human genome that could account for varying degrees of neuroticism. The genetic variants for happiness are mainly expressed in the central nervous system and the adrenal glands and pancreatic system.
The results were published in the journal Nature Genetics.
We all have a friend who is super happy, with an extra pep in their step. One that is always smiling and laughing, and who is the eternal optimist. This friend seems happier than the rest of us, and even predisposed to “walk on sunshine.”
This groundbreaking study, shows that happiness may be in the genes.
Specifically, their study found that how happy a person feels about his or her life can be influenced by the changes in DNA that make each of us unique.
"This study is both a milestone and a new beginning: A milestone because we are now certain that there is a genetic aspect to happiness and a new beginning because the three variants that we know are involved account for only a small fraction of the differences between human beings,” said Meike Bartels, a professor of Genetics and WellBeing at VU Amsterdam, in a statement.
Bartels, along with a group of nearly 200 scientists in 17 countries, examined common DNA variations in more than 300,000 different individuals to analyze phenotypes — observable traits resulting from interactions between genes and environment.
Their research explored subjective well-being (how happy a person thinks or feels about his or her life), depressive symptoms, and neuroticism. The project factored in mental health issues, and also five physical risk factors for adverse health outcomes that may affect a person's mood: body mass index (BMI), smoking status, coronary artery disease, fasting glucose levels and triglyceride levels.
The findings revealed subjective well-being, neuroticism and depression are predominantly influenced by the same set of genes. Three genetic variants are linked to happiness, which is mainly expressed in the central nervous system, adrenal glands, and pancreatic system.
Just two genetic variants can explain depression, and 11 are linked with neuroticism. The genetic variants identified only account for a small percentage of these genetic associations. Researchers also noted genes expressed in tissues that play a key role in hormone production were also affecting traits associated with well-being. This is in addition to genes that are expressed in the central nervous system.
“Hormones clearly have an important influence on the regulation of mood and stress,” said Professor Elina Hypponen, senior author, center director for Population Health Research at the University of South Australia and a principal fellow at the SA Health and Medical Research Institute (SAHMRI), in a statement.
The researchers also observed whether the genetic variants they identified overlapped with genetic variants associated with other diseases and disorders, including Alzheimer’s, anxiety, autism spectrum disorder, bipolar disorder and schizophrenia.
The strongest link proved to be with anxiety disorders, while the genetic variants tied to subjective well-being, depression, and neuroticism moderately overlapped with the variants linked to schizophrenia and bipolar disorder.
So what exactly drives happiness?
“Genetics is only one factor that influences these psychological traits. The environment is at least as important, and it interacts with the genetic effects,” said Daniel Benjamin, corresponding author and associate professor of the Center for Economic and Social Research at the University of Southern California Dornsife College of Letters, Arts and Sciences, in a statement.
This suggests psychological well-being is influenced by both genes and environment. The researchers hope locating these variants will allow them to better study the interaction between nature and nurture, as the environment is responsible for the differences in the way people experience happiness — to a certain extent.
Previous studies suggest genes account for about half of what makes people happy, or whether they are sociable, active, stable, hardworking, or conscientious.
In a 2008 study, researchers at the University of Edinburgh observed happiness levels and personality traits in more than 900 twin pairs. The findings showed identical twins shared more personality traits than a pair of non-identical twins, and when asked how happy they were, the identical pair responded more similarly. This suggests happiness and personality have a strong genetic component. However, these genes won’t guarantee happiness because this is also contingent on a variety of external factors, such as relationships, health, and careers.
There is a plethora of evidence on the influence of genes’ on happiness, but it’s important to remember there are many genes involved, and thousands of DNA variants for complex traits. So, there isn’t a gene for happiness, but there are many genes and these interact with our environmental experiences, which is what ultimately influences our happiness levels.
We can still change our outlook — even if we’re predisposed to be unhappy.
Depression, neuroticism, and sense of well-being may have genetic links Studying these traits in tandem could help us understand them better. The role of genetics in mental illness is a complex topic. On the one hand, evidence of genetic and biological causes for mental illnesses may help to fight the stigma that often accompanies them. On the other hand, certain researchers have suggested that a focus on genetics rather than traumatic life events can run the risk of ignoring the social ills that underlie or enhance many mental illnesses. Despite some ambiguous feelings, the work has gone on.
A genetic study recently published in Nature Genetics describes the results from the work of an eye-popping 190 scientists around the world. It describes an in-depth exploration of three separate traits: depression, neuroticism (the tendency to experience anxiety and fear easily), and subjective well-being (an experience of life satisfaction and/or happiness).
They found evidence suggesting that these three traits are influenced by some of the same genes and are linked to the pancreatic, adrenal, and central nervous systems. Tiny cumulative effects Psychology researcher Richard Bentall argues that genetic studies are fruitless; so many genes have been identified as playing a role in mental illness that their medical usefulness becomes diluted. And, even when the genetics are simple, it's not always helpful.
“Consider Huntington’s Disease, a terrible degenerative neurological condition that is caused by a single dominant gene with a known biological function,” he writes. “Many years after this gene was discovered there is still no sign of a medical therapy for this simplest of all the genetic conditions.” But the medical usefulness of genetic studies doesn’t begin and end with gene therapy. Understanding more about genetic contributors to mental illness can help us to understand the disorders themselves better, shining a light on the factors that influence them.
In a genome-wide association study (GWAS) like this one, the researchers look at differences scattered throughout people's genomes, trying to spot the ones that could be meaningful. We already know about locations in the human genome where there’s variation among people; by sweeping across all of these locations in enough people, it’s possible to identify the variants that appear more frequently in people who have an illness. It’s important to realize that this doesn’t mean that this variant is “the gene for depression” or anything so nice and simple; it could just be in a stretch of DNA near a relevant gene. And the gene itself may be less a cause than an influence; multiple genetic influences often interact with each other and with the environment, painting a complex causal picture.
Nonetheless, results from GWAS are a huge step toward untangling this convoluted causal chain. As it becomes possible to study more and more people, it’s also becoming feasible for each GWAS to detect weaker and weaker influences. Each genetic variant might be associated with only a tiny change in the overall level of risk, but with huge groups of people, it’s possible to detect more variants, building a more comprehensive picture. Links between traits Until this study, very few genetic variants had been found that linked to depression and neuroticism.
The authors suggest that this could be due to low sample sizes that didn’t have the power to detect very small, subtle effects. Although previous research has linked subjective well-being with depression, it hasn’t received much GWAS attention of its own. The researchers started out by analyzing subjective well-being in nearly 300,000 people, finding three genetic variants common to people with similar levels of contentment.
After analyzing neuroticism in more than 170,000 people and depression in more than 180,000 people, they came up with similar results: two genetic variants associated with depression and 11 associated with neuroticism. They replicated the test for depression in nearly 370,000 23andMe customers, finding the same thing.
The surprise came when the analyses revealed strong genetic correlations within the three traits, which suggests that they are all influenced by an overlapping set of genes. When they looked at what the genes involved do, they found that subjective well-being and depression were both linked to genes needed in pancreatic and adrenal tissues. In a comparison with various other conditions (including schizophrenia and coronary artery disease), similar patterns kept showing up. For instance, all three of the original conditions were strongly genetically linked to anxiety disorders.
While the variety of disorders associated with these genes is significant, each of the variants found in this study has a vanishingly tiny effect on its own.
“These effect sizes imply that, to account for even a moderate share of heritability, hundreds or (more likely) thousands of variants will be required,” the authors write. It’s likely that many variants evaded detection in this study, but they might turn up in future studies as the sample sizes get bigger and bigger. Altogether, though, the results point to a picture where a handful of genes contribute to a number of different mental illnesses and psychological traits. It’s possible that these genes don’t affect the traits themselves, so much as influence things like overall mood, which can underlie everything, the authors suggest. It’s far from a simple picture, but a study like this can give us a better idea of where to look to start filling in the blanks.
Genetic influences on happiness
Prior twin and family research using information from the Netherlands Twin Register and other sources has shown that individual differences in happiness and well-being can be partially ascribed to genetic differences between people. Happiness and wellbeing are the topics of an increasing number of scientific studies in a variety of academic disciplines.
Policy makers are increasingly focusing on wellbeing, drawing primarily on the growing body of evidence suggesting that wellbeing is a factor in mental and physical health.
VU Amsterdam professor Meike Bartels explains:
"This study is both a milestone and a new beginning: A milestone because we are now certain that there is a genetic aspect to happiness and a new beginning because the three variants that we know are involved account for only a small fraction of the differences between human beings. We expect that many variants will play a part."
Locating these variants will also allow us to better study the interplay between nature and nurture, as the environment is certainly responsible -- to some extent -- for differences in the way people experience happiness."
Further research is now possible
These findings, which resulted from a collaborative project with the Social Science Genetic Association Consortium, are available for follow-up research. This will create an increasingly clearer picture of what causes differences in happiness.
Professor Bartels points out that "The genetic overlap with depressive symptoms that we have found is also a breakthrough. This shows that research into happiness can also offer new insights into the causes of one of the greatest medical challenges of our time: depression."
The research effort headed by professors Bartels and Koellinger is the largest ever study into the genetic variants for happiness. It was successfully completed thanks to the assistance of 181 researchers from 145 scientific institutes, including medical centres in Rotterdam, Groningen, Leiden and Utrecht, and the universities of Rotterdam and Groningen.
“This study is both a milestone and a new beginning: a milestone because we are now certain that there is a genetic aspect to happiness and a new beginning because the three variants that we know are involved account for only a small fraction of the differences between human beings. We expect that many variants will play a part,”
Prof. Bartels said. “Happiness and wellbeing are the topics of an increasing number of scientific studies in a variety of academic disciplines,” the scientists said.
“Policy makers are increasingly focusing on wellbeing, drawing primarily on the growing body of evidence suggesting that wellbeing is a factor in mental and physical health.” According to the team, the genetic variants for happiness are mainly expressed in the central nervous system, the adrenal glands and pancreatic system.
“The genetic overlap with depressive symptoms that we have found is also a breakthrough,” Prof. Bartels said.
“This shows that research into happiness can also offer new insights into the causes of one of the greatest medical challenges of our time: depression.” “The findings are available for follow-up research,” the researchers said.
Source: Okbay A, Baselmans BML, De Neve JE et al. Genetic variants associated with subjective well-being, depressive symptoms, and neuroticism identified through genome-wide analyses. Nature Genetics. 2016.