The first introduction to psychology normally comes in the kind 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 physically function and, to a certain degree, how they behave or what illnesses they may develop. But very few of these students have an understandable comprehension of what exactly DNA is, where it is found in the body, why it causes problems, and how it can be manipulated or changed.
In the case of evolution, the genes passed from one generation to the next only need to survive. Genes are nothing more than instructions for doing things. Humans, as all living things, are programmed through thousands of years of natural selection to engage in behavior that is survival oriented. The basis for this programming is the expression of certain 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 behaviour.
Concerning understanding what is going on genetically, we are still in the era of molecular biology. In this frame, genes are simply packets of information carrying instructions. This is how humans, plants and animals have been evolving for centuries. Nevertheless, in the past 50 years or so, a revolution in the field of psychology has happened known as molecular biology or genomics. Genomics provides a new lens through which we could view the relationships between behaviour and genes.
The molecular basis for behaviors and human memory is in fact quite simple – it is all about the epigenome. The Epigenome is a mobile memory storage that determines whether or not 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. The majority 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 many years, autism research was based upon research on twins. However, it was found that there was substantial heritability (hitability) to behavior which existed between individuals who had identical twins but whose traits were quite different. This study provided the first evidence of the significance of the epigenome in human behavior and its connection to abnormal behavioral disorders like autism.
Although the importance of the Epigenome in psychology has been established, many in the psychological area are hesitant to accept its potential as a substantial factor in mental illness. One reason for this is it is difficult to define a real genetic sequence or locus that leads to a behavioral disorder. Another issue is that there are simply too many genetic differences between individuals to use a single DNA sequence to determine mental illness. Finally, although the research on the Epigenome has been promising, more work has to be done to find out the role that genetics play in complex diseases such as 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 knowing 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 today 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 also have been involved in studying the relationship between Epigenetics and Autism. My future posts will also discuss diseases of the brain which can be impacted by Epigenetics.