July 22, 2019
Science

How much does your DNA influence your Agreeableness?

Agreeableness is a measurable trait, which psychologists can quantify using a series of questions.
By
Tomohiro Takano

Agreeableness is a measurable trait, which psychologists can quantify using a series of questions. Essentially, agreeableness is a dimension of interpersonal relationships which includes altruism, trust, cooperativeness, and modesty. In simple terms, agreeableness is how likely you are to agree with others and cooperate.


While it should be obvious that your environment and upbringing contribute greatly to this trait, most people don’t know that their DNA directly determines a large portion. Specifically, scientists have measured that up to 50% of your personality is inherited through your genes. As such, it may be useful to analyze your genes to understand how they influence your personality traits, including agreeableness.


Is my agreeableness predetermined?

In a sense, yes it is.


While much of your personality is based on your experiences, upbringing, and environmental factors, there is a large genetic influence. Many proteins within your brain determine how the cells within your brain communicate and form new connections. How these neurons form determines what pathways your brain forms, and eventually what thoughts, feelings, and personality you have.


Some people are more prone to agreeableness, based partially on what proteins their genes encode for, and therefore how their neurons form. DNA analysis has identified several genes which may affect this trait. However, since only around 50% of your personality is inherited, the other half is learned.


Agreeableness is a complex trait influenced by a wide variety of genetic components. However, it is also a very malleable trait. Not only does it change depending on environmental factors, but it also changes in people over time. In general, as people get older they become more agreeable.


How does DNA influence a person’s Agreeableness?

Several different meta-studies have analyzed Agreeableness and the other big five personality traits to try to determine links to genetic variants. In one study, Agreeableness was most related to the CLOCK gene. This gene has also been correlated to the circadian rhythm. The circadian rhythm is like your internal clock, which sets your waking and sleep cycles. Interestingly, it has also been shown that agreeableness is also related to traits such as being a “morning person”, which would support the involvement of genes controlling the circadian rhythm.


Another study showed that several genetic variants of the DRD3 gene are highly correlated with Agreeableness in the five-factor model of personality. This gene is highly expressed within the limbic system, a region of the brain which controls many behaviors and other big five personality traits. So, having certain genetic variants in this gene can increase or decrease various personality dimensions, such as agreeableness.


While both of these findings are intriguing, both need more evidence to fully understand the genetic components of the five-factor model of personality. Both studies were done on relatively small populations, each isolated to a small geographic area. As more studies are done, more correlations may be found which contribute to agreeableness or other personality traits.


Common Questions

Agreeable is indeed a complex trait. As such, people often have many questions on how DNA actually affects their personality traits. Below are answers to some common questions about agreeableness and DNA, and some answers.


My environment is what has been more influential in my personality and who I am, so this doesn’t matter.

Well, you are right in some ways. Your environment is extremely important in determining your personality traits and overall outlook on life. However, your genes directly control the various proteins expressed in your brain, and how your brain cells connect and communicate. While it may feel like you are agreeable because of your upbringing, you may simply share a set of genes with your parents. Environmental factors may have played a stronger role, but there is definitely a genetic influence on how your brain processes information and creates personality traits.


It’s the people I’m around that make me more or less agreeable, not my genes!

Again, you can’t prove that. Like the chicken and the egg, our environment and genes constantly interact and influence each other. Certain people are disagreeable, for sure. But, how you deal with these people is partly environmental and partly genetic. Agreeability is a complex trait which has many influences! Further, many genes and genetic variants have not been identified that may affect your personality traits. As science progresses, we will gain a better understanding of exactly what affects personality dimensions in different people.


Looking ahead

While the two studies mentioned in this article were small and focused on isolated populations, larger studies will lead to even more connections between personality types and genetic influences. In fact, both the personality test and the genetic analysis will be improved in the future. Scientists have already identified over 112 SNPs related to agreeableness, and many more may be found going forward. This is an enormously complex trait that will take much more study to fully understand.


Find out what your DNA says

If you are interested in how your DNA may be affecting your personality traits, use Genomelink to analyze which genetic variants you may have which influence your big five personality dimensions. While these are complex traits that are also influenced by environmental factors, knowledge of how your genes are influencing those traits can give you a leg up in changing them. All personality traits are malleable, given enough practice. However, it is also beneficial to know if you will be fighting a natural genetic influence. Check Genomelink now to learn about how agreeable your DNA predisposes you to be!

To find out more DNA upload sites, check out our article "The Best DNA Upload Sites"


Tomohiro Takano
Tomohiro Takano
Co-Founder and CEO