The first introduction to psychology normally comes in the kind of biology classes. Many biology students already come into class with at least basic knowledge of psychology. They understand that their genes determine how their bodies work, how they function and, to a certain degree, how they act or what illnesses they might develop. But hardly any of these students have a clear understanding of what exactly DNA is, where it is found in the body, why it causes problems, and how it can be manipulated or altered.
In the case of evolution, the genes passed from one generation to the next just have to survive. Genes are nothing more than 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, 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 framework, genes are simply packets of information carrying directions. This is how humans, plants and animals have been evolving for thousands of years. However, in the past 50 years or so, a revolution in the field of psychology has occurred known as molecular biology or genomics. Genomics provides a new lens through which we could see the relationships between behavior and genes.
The molecular basis for behaviors and human memory is actually quite simple – it’s all about the epigenome. The Epigenome is a mobile memory storage that determines whether a behavior will 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 cellular memory storage of the person. The copy of the gene which determines the behavior is called 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 people who had identical twins but whose traits were very different. This study provided the first evidence of the importance of the epigenome in human behaviour and its link to abnormal behavioral disorders like autism.
Although the significance of this Epigenome in psychology was established, many in the psychological area are reluctant to accept its potential as a substantial factor in mental illness. One reason for this is it is hard 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 needs to be done to find out the role that genetics play in complex diseases such as schizophrenia. If this finding holds true, it can be used as a foundation for analyzing other complicated diseases that have complicated 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 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 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 brain which can be affected by Epigenetics.