The first introduction to psychology normally comes in the form of biology classes. Many biology students already come into class with at least basic knowledge of psychology. They know that their genes determine how their bodies work, how they physically 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 changed.
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. 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 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 going on genetically, we are still in the era of molecular biology. Within this framework, genes are just packets of information carrying directions. This is the way 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 actually quite simple – it is 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 amounts. 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 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 shown 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 which existed between individuals who had identical twins but whose traits were very different. This study provided the first evidence of the significance of the epigenome in human behavior and its connection to abnormal behavioral disorders such as autism.
Although the importance of the Epigenome in psychology has been established, many in the emotional field are reluctant to accept its potential as a significant factor in mental illness. One reason for this is that it is hard to define an actual genetic sequence or locus that causes a behavioral disorder. Another problem is that there are simply 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 may be utilised as a basis for analyzing other complex 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 site discusses the exciting new technologies that are available today to better understand how Epigenetics affects behavior and the susceptibility to disease. You can even 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 analyzing the relationship between Epigenetics and Autism. My future posts will also talk about diseases of the brain which can be impacted by Epigenetics.