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 know that their genes determine how their bodies work, how they physically function and, to a certain extent, how they behave or what illnesses they may develop. But very few 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 participate in behavior that’s survival oriented. The basis for this programming is 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.
In terms of understanding what is going on genetically, we’re still in the age of molecular biology. Within this frame, genes are simply packets of information carrying instructions. This is the way humans, plants and animals have been growing for centuries. Nevertheless, in the past 50 years or so, a revolution in the field of psychology has occurred 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 human and behaviors memory is actually quite simple – it’s all about the epigenome. The Epigenome is a cellular 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 behavior exists in all of us, but in varying quantities. 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 known as the epigome. It is 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 years, autism research was based upon research on twins. However, it was discovered 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 significance of the epigenome in human behavior and its link to abnormal behavioral disorders such as autism.
Even though the importance of this Epigenome in psychology was established, many in the psychological field are hesitant to accept its potential as a substantial factor in mental illness. One reason for this is that it is difficult to define an actual genetic sequence or locus that causes a behavioral disorder. Another issue is that there are just 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 determine the role that genetics play in complex diseases such as schizophrenia. If this finding holds true, it may be used as a foundation for analyzing other complicated diseases that have complex genetic components.
If you’re interested in learning 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 ecological 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 affected by Epigenetics.