The first introduction to psychology usually comes in the form of biology classes. Many biology students already come into class with at least basic understanding of psychology. They understand that their genes determine how their bodies work, how they physically function and, to a certain extent, how they act or what illnesses they might develop. But very few of these students have a clear understanding of what exactly DNA is, where it’s found in the body, why it causes problems, and how it can be manipulated or altered.
In the case of development, the genes passed from one generation to the next just have to survive. Genes are merely instructions for doing things. People, as all living things, are programmed through thousands of years of natural selection to engage in behavior that is survival oriented. The foundation for this programming is that the expression of specific genes that cause specific traits, such as aggressiveness, violence or sexuality. In the case of psychology, the genes that are passed on to us through our parents, grandparents, or other kin will determine such behavior.
Concerning understanding what is happening genetically, we are still in the era of molecular biology. Within this framework, genes are just packets of information carrying instructions. This is how humans, plants and animals have been evolving for centuries. However, in the last 50 years or so, a revolution in the field of psychology has happened known as molecular biology or genomics. Genomics offers a new lens through which we can view the relationships between behavior and genes.
The molecular basis for behaviors and human memory is in fact quite simple – it’s all about the epigenome. The Epigenome is a cellular memory storage that determines whether a behavior is going to be expressed or not. Like all memory storage systems, it contains information that is “programmed” in advance by the genome.
What we now know is that the genetic material that determines behavior exists in all of us, but in varying quantities. Most of the variations come from the variation in the copies of genes inside the cellular memory storage of the individual. The copy of the gene which determines the behavior is known as the epigome. It is this specific copy that we call the epigenome.
The significance of the epigenome in psychology and its relationship to individual differences has been revealed in a landmark study on twins. For years, autism research was based upon research on twins. However, it was discovered that there was substantial heritability (hitability) to behavior that existed between individuals who had identical twins but whose traits were quite different. This study provided the first evidence of the importance of the epigenome in human behaviour and its link to abnormal behavioral disorders such as autism.
Even though the significance of this Epigenome in psychology was established, many in the psychological field are hesitant to accept its potential as a substantial factor in mental illness. 1 reason for this is that it is difficult to define a real genetic sequence or locus that leads to a behavioral disorder. Another issue is that there are just too many genetic differences between individuals to use a single DNA sequence to determine mental illness. Finally, although the study on the Epigenome has been promising, more work needs to be done to determine the role that genetics play in complex diseases such as schizophrenia. If this finding holds true, it can be used as a basis for studying other complicated diseases that have complex genetic components.
If you are interested in knowing more about Epigenetics and how it applies to psychology, I highly recommend that you follow the links below. My website discusses the exciting new technologies that are available now to better understand how Epigenetics affects behavior and the susceptibility to disease. You can also hear me speak on my epigenetics and autism blog. My research into Epigenetics is centered on understanding the ecological causes of disease, but I also have been involved in studying the relationship between Epigenetics and Autism. My future articles will also discuss diseases of the mind that can be affected by Epigenetics.