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 function and, to a certain extent, how they behave or what illnesses they might develop. But hardly any of these students have an understandable 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 merely instructions for doing things. People, as all living things, are programmed through thousands of years of natural selection to participate in behavior that is survival oriented. The basis 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.
Concerning understanding what is happening genetically, we are still in the era of molecular biology. Within this frame, genes are just packets of information carrying directions. This is how humans, plants and animals have been evolving for centuries. 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 view the relationships between behavior and genes.
The molecular basis for human and behaviors memory is in fact quite simple – it is all about the epigenome. The Epigenome is a cellular 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 individual. The copy of the gene which determines the behaviour is called the epigome. It is this particular copy that we call the epigenome.
The importance of the epigenome in psychology and its relationship to individual differences has been 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 that 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 like autism.
Although the significance of the Epigenome in psychology has been established, many in the psychological field are reluctant to accept its potential as a significant element in mental illness. 1 reason for this is it is hard to define an actual genetic sequence or locus that leads to a behavioral disorder. Another issue is that there are simply too many genetic differences between people 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 utilised 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 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 ecological 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 that can be affected by Epigenetics.