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Week 4: Nature and Nurture Revisited: Epigenetics and the Microbiome

Think back to when you first learned about the “nature versus nurture” debate. The historical nature versus nurture debate was concerned with the relative importance of an individual’s innate qualities (nature) versus his or her personal experiences (nurture) in determining or causing differences in physical appearance, behavior, cognition, and emotion.

It has become increasingly clear that these qualities are not solely attributable to nature or nurture; rather, it is now recognized that nature and nurture interact to influence outcomes. The relatively new science that studies this phenomenon is called epigenetics. There is also increasing evidence that the “brain” in our gut, called the microbiome, also influences mental health, behavior, and health outcomes; this starts before we are born and is also influenced by how we are born.

This week, you examine the connection of nature versus nurture to epigenetics and the microbiome, while also considering the personal and social implications of these fields of study. You also examine the idea of contributing to positive social change from a professional perspective in the fourth section of your Capstone Paper.

Learning Objectives

Students will:

• Evaluate the influence of epigenetics and the microbiome on the nature versus nurture debate
• Evaluate the social implications of epigenetic and microbiome research 
• Analyze relationship of positive social change to a professional context
• Integrate psychological theories and concepts in Capstone Paper

Learning Resources

Required Readings

Document: Expanding our understanding of social change: A report from the definition task force of the HLC special emphasis project (PDF).

Callahan, D., Wilson, E., Birdsall, I., Estabrook-Fishinghawk, B., Carson, G., Ford, S., Yob, I. (2012).
Minneapolis, MN: Walden University.

Carlson, A., Kai Xia, M. Azcarate-Peril, A.,  Goldman, B., Ahn, M.,Styner, M., Thompson, A.,  Geng, X., Gilmore, J., and Knickmeyer, R.  (2018). Infant Gut Microbiome Associated With Cognitive Development. Biological Psychiatry, 83:148–159. 

Champagne, F. A., & Mashoodh, R. (2009). Genes in context: Gene-environment interplay and the origins of individual differences in behavior. Current Directions in Psychological Science, 18(3), 127–131.

Roth, T. L., & Sweatt, J. D. (2011). Annual research review: Epigenetic mechanisms and environmental shaping of the brain during sensitive periods of development. Journal of Child Psychology and Psychiatry, 52(4), 398– 408.

Svoboda, E (2020). Could the gut microbiome be linked to Autism? Nature 577, S14-S15. Retrieved from: https://www.nature.com/articles/d41586-020-00198-y

Mueller, N., Bakacs, E., Combellick, J., Grigoryan, Z., and Dominguez-Bello, M. (2015). The Infant Microbiome Development: Mom Matters. Trends in Molecular Medicine, 21(2), 109-117.

Weir, K (2018). The Future of Psychobiotics. Monitor on Psychology, 49(11), 43. Retrieved from: https://www.apa.org/monitor/2018/12/cover-psychobiotics

Required Media

TED Conferences, LLC (Producer). (2012). Epigenetics makes you unique [Video file]. Retrieved from https://www.youtube.com/watch?v=JTBg6hqeuTg

Note:  The approximate length of this media piece is 18 minutes.

TEDx Conferences, LLC (Producer). (2015). Food for thought: How your belly controls your brain [Video file]. Retrieved from https://www.youtube.com/watch?v=awtmTJW9ic8
Note: The approximate length of this media piece is 15 minutes.

Optional Resources

Santavirta, T., Santavirta, N., Gilman, S. (2018). Association of the World War II Finnish Evacuation of Children With Psychiatric Hospitalization in the Next Generation. JAMA Psychiatry. 2018;75(1):21-27 Retrieved from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5833542/

Discussion: Nature Versus Nurture: Epigenetics and the Microbiome 

Epigenetics is the study of changes in gene activity that do not involve direct alterations to the actual genetic code. There is a relationship between genes and traits, and the bridge between the gene or genes underlying a trait is a protein. Genes are the code for building proteins, and once built, proteins carry about many functions in the body and they are ultimately responsible for behavioral traits. How is it decided what specific genes get turned on or off? The patterns of gene expression (protein manufacture) are governed by the cellular material—the epigenome—that sits on top of the genome, just outside it (hence the prefix , which means “above”). It is these epigenetic “marks” that tell certain genes to switch on or off. It is through epigenetic marks that environmental factors like diet, stress, and prenatal nutrition can make an imprint on genes, and this imprint can be passed on over generations. With epigenetic changes, the DNA itself does not change, but the way individual genes within the sequence are expressed (or turned on or off) does change.

If you chose the microbiome, read about  how the infant gut microbiome is associated with brain development, cognitive development, mental health, including autism, language, and the immune system. For this Discussion, consider the personal and social implications of a healthy microbiome, both for you and infants that are yet to be born. 

Alternatively, the infant microbiome has been shown to play a role in future health, and this is influenced by the exchange of maternal microbes. There is evidence that this is even linked to autism and other developmental aspects such as communication and cognitive performance.

If you chose to write about the Microbiome: Explain how microbiome research provides a new perspective on the nature versus nurture debate. Discuss how the infant microbiome is related to future development of a child, including cognition and health. In addition, explain the broader social implications of this type of research. Finally, share your prediction of and rationale for what future microbiome research may discover.