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 know that their genes determine how their bodies work, how they function and, to a certain degree, how they behave or what illnesses they might develop. But hardly any 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 changed.
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’s 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, siblings, or other kin will determine such behavior.
In terms of understanding what is going on genetically, we’re still in the era of molecular biology. In this framework, genes are simply packets of information carrying directions. This is the way humans, plants and animals have been growing 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 actually quite simple – it is all about the epigenome. The Epigenome is a cellular memory storage which 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 amounts. The majority of the variations come from the variation in the copies of genes within the mobile memory storage of the individual. The copy of the gene which determines the behaviour 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 was shown in a landmark study on twins. For years, autism research was based upon research on twins. However, it was found that there was substantial heritability (hitability) to behavior which existed between people who had identical twins but whose traits were quite different. This study provided the first evidence of the significance of the epigenome in human behaviour and its connection to abnormal behavioral disorders like 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 significant element in mental illness. One reason for this is that it is difficult to define an actual genetic sequence or locus that causes a behavioral disorder. Another problem is that there are just too many genetic differences between people to use a single DNA sequence to determine mental illness. Finally, although the research on the Epigenome has been promising, more work needs to be done to determine the role that genetics play in complex diseases like schizophrenia. If this finding holds true, it may be used as a foundation for studying other complex diseases that have complex genetic components.
If you are interested in learning more about Epigenetics and how it applies to psychology, I strongly advise that you follow the links below. My site 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 focused on understanding the environmental causes of disease, but I have also been involved in studying the relationship between Epigenetics and Autism. My future posts will also discuss diseases of the mind that can be impacted by Epigenetics.