Jessica D. Ayers: As a species, humans like to think we have complete control over our decisions and behavior. But just beneath the surface, forces beyond our conscious control influence how we think and behave: our genes.
Since the 1950s, scientists have been studying the influence of genes on human health. This has led doctors, researchers, and policymakers to advocate the exploit of precision medicine to personalize disease diagnosis and treatment, leading to faster improvements in patient well-being.
However, the influence of genes on psychology has been overlooked.
My research examines how genes influence human psychology and behavior. Here are some specific ways psychologists can exploit genetic conflict theory to better understand human behavior—and potentially advance treatment for psychological problems.
What do genes have to do with it?
The theory of genetic conflict posits that even though our genes come together to make us who we are, they retain markers that indicate whether they came from mom or dad. These markers cause the genes to either work together or fight with each other as we grow and develop.
Research on genetic conflicts has focused primarily on pregnancy because it is one of the few moments in human development when the influence of different sets of genes can be clearly observed in one individual.
Maternal and paternal genes usually have different ideal strategies for growth and development.
While mom and dad's genes eventually find ways to work together, resulting in normal growth and development, those genes also benefit by stimulating the development of the fetus to be a little more in line with what is optimal for the parent they came from.
The mother's genes work to ensure that the mother is robust and has sufficient resources for another pregnancy, while the father's genes benefit from the fact that the fetus takes all of the mother's resources for itself.
However, if the genes are unable to prevent this, it can result in undesirable consequences, such as physical and mental disabilities in the child or even miscarriage.
Although genetic conflict is a normal phenomenon, its impact has been largely overlooked in psychology. One reason is that researchers assume that genetic cooperation is necessary for an individual's health and well-being.
Another reason is that most human traits are controlled by multiple genes. For example, height is determined by a combination of 10,000 genetic variants, and skin color is determined by more than 150 genes.
The elaborate nature of psychology and behavior makes it tough to pinpoint the unique influence of a single gene, let alone which parent it comes from. Take depression, for example.
The likelihood of developing depression is influenced not only by 200 different genes but also by environmental factors, such as childhood abuse and stressful life events. Scientists have also studied similar elaborate interactions in stress- and anxiety-related disorders.
Prader-Willi and Angelman syndromes
When scientists study genetic conflicts, they typically focus on their association with disease, unwittingly documenting the impact of genetic conflicts on psychology.
Specifically, the researchers investigated how extreme cases of genetic conflict—for example, when the influence of one set of parental genes is fully expressed and the other set is completely silenced—are linked to changes in behavior, studying people with Prader-Willi syndrome and Angelman syndrome.
Prader-Willi and Angelman syndromes are occasional genetic disorders that affect about 1 in 10,000 to 30,000 and 1 in 12,000 to 20,000 people worldwide, respectively. There is currently no long-term treatment for either condition.
These syndromes develop in patients who are missing one copy of a gene on chromosome 15, which is needed for balanced growth and development. A person who inherits only the version of the gene from their father will develop Angelman syndrome, while a person who has only the version of the gene from their mother will develop Prader-Willi syndrome.
Physical characteristics of Angelman syndrome include severe developmental delays, intellectual disabilities, mobility problems, eating problems, and excessive smiling. Physical characteristics of Prader-Willi syndrome include decreased muscle tone, feeding difficulties, hormone deficiencies, brief stature, and extreme overeating in childhood.
These syndromes represent one of the few cases in which the influence of a single missing gene can be clearly observed. While both Angelman and Prader-Willi syndromes are associated with problems with language, cognition, eating, and sleeping, they are also associated with marked differences in psychology and behavior.
For example, children with Angelman syndrome smile, laugh, and generally want to engage in social interactions. These behaviors are associated with an increased ability to obtain resources and investment from those around them.
Children with Prader-Willi syndrome, on the other hand, experience outbursts of anger, anxiety, and have difficulties in social situations.
These behaviors are associated with increased maternal difficulties early in an individual's life, potentially delaying the time when the mother will have another child. This would therefore boost the child's access to resources such as food and parental attention.
Genetic conflict in psychology and behavior
Angelman syndrome and Prader-Willi syndrome underscore the importance of studying the impact of genetic conflict on psychology and behavior. Researchers have documented differences in temperament, sociability, mental health, and attachment in these disorders.
The differences in psychological processes between these disease syndromes resemble the presumed effects of genetic conflict.
Genetic conflict influences the bond by determining the responsiveness and sensitivity of the parent-child relationship through differences in behavior and resource requirements.
This relationship begins to form while the baby is still in the womb and helps determine how the baby will respond to different social situations.
While this response calibration begins on a purely biological level in the womb, it results in unique patterns of social behavior that influence everything from how we deal with stress to our personality.
Because most scientists do not consider the impact of genetic conflict on human behavior, much of this research is still theoretical. Scientists have had to find parallels between disciplines to see how the biological process of genetic conflict affects psychological processes.
Research on Angelman and Prader-Willi syndromes is just one example of how incorporating the concept of genetic conflict into psychological research can provide scientists with an opportunity to explore how our biology makes us uniquely human.
Jessica D. Ayers, Assistant Professor of Psychological Sciences, Boise State University
This article was reprinted from Conversation under the Creative Commons license. Read original article.
Image Source: Pixabay.com
