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 degree, how they behave 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 changed.
In the case of development, the genes passed from one generation to the next just need to survive. Genes are merely 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 foundation for this programming is that 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, grandparents, or other kin will determine such behavior.
Concerning understanding what is happening genetically, we are still in the age of molecular biology. Within this frame, genes are simply packets of information carrying directions. This is the way humans, plants and animals have been evolving for thousands of years. Nevertheless, in the last 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 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 mobile memory storage which determines whether or not 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 behaviour exists in all of us, but in varying amounts. The majority of the variations come from the variation in the copies of genes inside the mobile memory storage of the individual. The copy of the gene that determines the behavior is called the epigome. It is this specific copy that we call the epigenome.
The importance of the epigenome in psychology and its relationship to individual differences was shown in a landmark study on twins. For many years, autism research was based upon research on twins. However, it was discovered 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 importance of the epigenome in human behaviour and its link to abnormal behavioral disorders such as autism.
Although the importance of this Epigenome in psychology has been established, many in the psychological field are reluctant 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 causes a behavioral disorder. Another problem 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 has 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 studying other complex diseases that have complicated genetic components.
If you’re 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 focused on understanding the environmental causes of disease, but I also have been involved in analyzing the relationship between Epigenetics and Autism. My future articles will also talk about diseases of the brain that can be affected by Epigenetics.