The first introduction to psychology normally 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 extent, how they behave or what illnesses they may develop. But hardly any of these students have an understandable understanding of what exactly DNA is, where it’s found in the body, why it causes problems, and how it can be manipulated or altered.
In the case of development, the genes passed from one generation to the next just need 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 participate in behavior that’s 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, siblings, or other kin will determine such behaviour.
In terms of understanding what is going on genetically, we’re still in the era of molecular biology. In this frame, genes are simply packets of information carrying directions. This is how humans, plants and animals have been growing for thousands of years. Nevertheless, 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 could see the relationships between behaviour and genes.
The molecular basis for behaviors and human memory is actually quite simple – it’s all about the epigenome. The Epigenome is a cellular 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 amounts. The majority of the variations come from the variation in the copies of genes inside the cellular memory storage of the person. The copy of the gene that determines the behavior is called the epigome. It’s this particular copy that we call the epigenome.
The significance of the epigenome in psychology and its relationship to individual differences was revealed 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 very 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.
Although the significance of this Epigenome in psychology was established, many in the psychological field are reluctant to accept its potential as a substantial factor in mental illness. One reason for this is that it is hard to define an actual genetic sequence or locus that leads to 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 determine the role that genetics play in complex diseases like schizophrenia. If this finding holds true, it can be used as a foundation 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 strongly advise that you follow the links below. My website 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 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 talk about diseases of the brain that can be affected by Epigenetics.