Running Head: THE INFLUENCE OF GENETICS ON HAPPINESS
The Influence of Genetics on Happiness
Stephanie Coates
Saginaw Valley State University
English 212: Pursuits of Happiness
1
THE INFLUENCE OF GENETICS ON HAPPINESS
Abstract
For the past decade, scientists have been researching and hypothesizing the factors that
compile an individual’s happiness. The components that affect this new area of study, known as
positive psychology, has been disagreed upon by many biologists and psychologists over the
years. Based off of research conducted, 35-50% of an individual’s happiness is correlated strictly
to their genetic makeup. An additional 8% of happiness is associated with the individual’s
circumstantial factors, which include education, income, profession, marital status and religion.
The remaining percentage of happiness is based upon the “ups and downs” that an individual
will experience throughout life. Many researchers have proved that an individual can only reach
a maximum or minimum level of happiness for a short amount of time and for the duration of
their life, will remain at a genetically determined level of happiness (Blum et al., 2012).
However, many would dispute this claim, reporting that people experience increased happiness
levels due to a circumstantial factor such as income, marital status or education. Since levels of
happiness can only be determined by the opinions of individual’s rating their own happiness,
scientists believe that results will continue to vary until all genetic components are able to be
identified. As molecular genetics and genetic testing methods improve, the influence of genes on
happiness can only become stronger.
THE INFLUENCE OF GENETICS ON HAPPINESS
Background
The human genome consists of approximately 21,000 genes that are separated onto a total
of 46 chromosomes, two sets of 22 autosomes and two sex chromosomes, X and Y (Fredrickson
et al,. 2013). Humans are diploid organisms, which means that each chromosome has a homolog,
or an identical match. All individuals are born with the same set of genes, however, gene
expression differs in all people. These differences in gene expression is what causes all
individuals to have different physical characteristics, which is genetically known as their
phenotype. Scientists refer to changes in gene expression as mutations. The word mutation is
generally thought of as a negative aspect in DNA, deoxyribonucleic acid, such as a mutation
causing Down Syndrome or Cystic Fibrosis. However, mutations occur in all individuals and the
majority of them do not have negative effects. There are several genetic mechanisms that cause
mutations to occur during cellular replication, mitosis, including inversions, duplications,
insertions and deletions. A combination of these mutations along with the environment that an
individual is raised in will contribute to their phenotype.
Over the past decade, scientists from several different fields have begun to focus on the
science of happiness and specifically the genetic components of happiness. In order to conduct
this research, studies have been performed on identical twins that were separated at birth and on
large families. These approaches to research allow scientists to analyze how genes affect the
happiness of an individuals with identical DNA that were raised in different environments
(Rietveld et al., 2013). During each of the conducted studies, all other varying health factors
were taken out of the data in order to obtain accurate, unbiased results. Some of these attributes
include age, weight, height, abuse history, tobacco or alcohol use and mental disorders. Although
the science of molecular genetics has tremendously improved over the past decade, there are still
THE INFLUENCE OF GENETICS ON HAPPINESS
more advancements that need to be made in order for all genes within the human genome to be
sequenced and their function to be identified (Chen et al., 2013). Genetic information is a key
factor in the level of happiness that an individual is able to reach, however, all of the genes
involved in this have not been identified at this point in time. In the future, advances in genetic
testing will help improve DNA sequencing and can provide more information on the specific
function of each gene in the human genome.
Happiness Genes
Based on previous research conducted, genetic information has proven to be responsible
for 35-50% of an individual’s happiness. Genes are responsible for influencing characteristics
such as personality, coping with stress, depression and anxiety. However, only 8% of happiness
is based on the circumstantial factors that differ throughout each person’s life, such as education,
income, profession, religion and marital status. The remaining percentage comprising an
individual’s happiness is the general “ups and downs” of life that everyone experiences on a
regular basis (Blum et al., 2012). In many situations, scientists refer to happiness as an
individual’s well-being. This aspect of a person’s life can be separated into two categories,
hedonic well-being and eudaimonic well-being. Hedonic well-being is described as the
experiences that have made a positive impact on an individual’s life, whereas eudaimonic wellbeing represents finding meaning and purpose in life without looking for self-gratification
(Fredrickson et al., 2013). Multiple studies have discovered a specific genes relating to increased
well-being as well as increased happiness among individuals, more specifically in women and
teenagers (Chen et al., 2013).
A study conducted by Fredrickson et al., 2013, reported that the variation in the
expression of several different genes led to either increased hedonic well-being or increased
THE INFLUENCE OF GENETICS ON HAPPINESS
eudaimonic well-being among individuals. Increased eudaimonic well-being was associated with
down-regulation of the CTRA gene, up-regulation of antibody synthesis genes and up-regulation
of Type I IFN response genes. In contrast, higher levels of hedonic well-being were associated
with up-regulation of the CTRA gene, up-regulation of proinflammatory genes and downregulation of antibody synthesis genes. These findings prove that based on the different
expression of these genes, an individual in more or less likely to be satisfied with their life and
enjoy the events that occur on a daily basis. The genetic testing that was used to discover the
results included DNA sequencing using assays of the individual’s involved in the study,
compared to a control individual. This allowed researchers to identify the four specific genes
mentioned above and how their expression differed on the individuals’ chromosomes that were
analyzed.
Additionally, a study performed by Chen et al., 2013, identified another gene that has
been proven to be linked to happiness within women. The MAOA gene, Monoamine oxidase A,
in the human genome is known to be involved with mood regulation. This gene is identified as a
catabolic enzyme of several neurotransmitters, including serotonin, dopamine and noradrenalin.
Since this gene is located on the X chromosome, this allows it to have a variable number of
polymorphisms (changes) that will result in different genotypes. These include the low activity
allele genotype, MAOA-L and the high activity allele genotype, MAOA-H. After individuals
were given a survey to “rank” their happiness level, their DNA was obtained from a saliva
sample and a polymerase chain reaction (PCR) was used to sequence the MAOA gene. The
results proved that women with higher expression of the MAOA-L allele are more sensitive to
positive environmental aspects and have a lower risk of developing stress and depression.
Women with higher expression of the MAOA-H allele prove to have increased risk for
THE INFLUENCE OF GENETICS ON HAPPINESS
depression and suicide, as well as resistance to many forms of treatment for depression.
Surprisingly, the MAOA-L and MAOA-H allele expression did not have any significant
correlation to happiness in men. Based on these findings, scientists have begun to ask themselves
another question, is there a possibility that women may be happier with their lives than men? At
this time, further research still needs to be conducted in order to obtain qualitative and
quantitative evidence of this speculation.
There are two other genes that scientists are aware of that have been correlated with
happiness. However, the specific details associated with these genes and how their expression
influences happiness are still being studied. The 5- HTTLPR gene is located on chromosome 17
and is known to make a molecule that acts as a transporter for serotonin, a neurotransmitter (De
Neve, 2012). The gene has been found to be associated with life satisfaction (Chen et al., 2013).
If an individual expresses two long versions of this gene, the process of transporting serotonin
will increase. This is correlated with an increase in life satisfaction, based on the teenage
individuals that were used in the study. The individuals who express two short versions of this
gene, reported less satisfaction in their lives (De Neve, 2012). Additionally, the Oxytocin
receptor gene (OXTR) has been found to be associated with self-esteem. Therefore, increased
expression of this gene leads to increased self-esteem and confidence, which scientists report will
evolve into happiness (Chen et al., 2013).
Counterargument
Although these research studies supply adequate information to prove the association
between genetic information and happiness, there are still those that disagree with this claim.
McBride, 2010, reports that individuals who participated in a survey related to income and
happiness, agreed that a higher income will provide more happiness in life. A higher income
THE INFLUENCE OF GENETICS ON HAPPINESS
suggests to individuals that they will be able to “buy” their happiness, whether it be spending
money on a new house, going on vacation or attracting a mate due to the amount of money an
individual possesses. An additional aspect discussed in this study referred to expectations in
relation to happiness. Individuals who took the survey, also reported that if their job met their
expectations in regards to a high salary, it improved their overall happiness level. Even though
these aspects may have some truth behind them, the genetics of these individuals were not
analyzed to discover if any specific genes were over or under expressed within their genome that
could also be contributing to their happiness. In addition to this, an individual’s level of
happiness is very subjective and cannot be strictly based off of data or facts. Different events that
occur throughout life may cause one person to be happy for several weeks, whereas it may only
make another individual happy for a few minutes. Due to this, it is hard to discern how happiness
correlates to circumstantial factors because there is not any scientific data or evidence to support
those theories.
Conclusion
Overall, genetic information is a very important factor in regards to an individual’s
happiness. Although some believe that happiness is not genetically programmed into the human
body, research studies have proven that there are specific genes associated with higher levels of
happiness and well-being among individuals. As technology continues to improve in the future,
it will only advance the study of molecular genetics and allow scientists to identify more genes
that contribute to happiness. Eventually, this may allow for improvements in medication to treat
depression and maybe even the development of medication that can improve happiness among
individuals who have the low expression of a specific gene. The possibilities of improving
THE INFLUENCE OF GENETICS ON HAPPINESS
happiness are endless once these genes become identified and who would not want to live a
happier lifestyle?
THE INFLUENCE OF GENETICS ON HAPPINESS
References
Blum, K., Oscar-Berman, M., Bowirrat, A., Giordano, J., Madigan, M., Braverman, E. E., &
Barh, D. (2012, April 13). Neuropsychiatric genetics of happiness, friendships, and
politics: Hypothesizing homophily as a function of reward gene polymorphisms. J. Genet
Syndrome Gene Therapy, 112(3).
Chen, H., Pine, D. S., Ernst, M., Gorodetsky, E., Kasen, S., Gordon, K., & Goldman, D. (2013).
The MAOA gene predicts happiness in women. Progress in Neuro-Psychopharmacology
& Biological Psychiatry, 40, 122-125.
De Neve, J. (2012, May 14). Happiness gene found in US teens. New Scientist, 17
Fredrickson, B. L., Grewen, K. M., Coffey, K. A., Algoe, S. B., Firestine, A. M., Arevalo, J. M.,
& Ma, J. (2013, August 13). A functional genomic perspective on human well-being.
PNAS, 110(33), 13684-13689.
McBride, M. (2010). Money, happiness, and aspirations: An experimental study. Journal of
Economic Behavior & Organization, 74, 262-276.
Rietveld, C. A., Cesarini, D., Benjamin, D. J., Koellinger, P. D., De Neve, J., Tiemeier, H., &
Johannesson, M. (2013, June 11). Molecular genetics and subjective well-being. PNAS,
110(24), 9692-9697.