The first introduction to psychology usually comes in the kind of biology classes. Many biology students already come into class with at least basic knowledge 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 altered.
In the case of development, the genes passed from one generation to the next only need 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’s survival oriented. The basis 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, siblings, or other kin will determine such behavior.
Concerning understanding what is happening genetically, we’re still in the era of molecular biology. In this framework, genes are just packets of information carrying directions. This is how humans, plants and animals have been growing for thousands of years. However, 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 behaviour 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 cellular memory storage which 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 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 cellular memory storage of the individual. The copy of the gene that determines the behaviour is called the epigome. It’s this particular 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 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 quite different. This study provided the first evidence of the importance of the epigenome in human behaviour and its connection to abnormal behavioral disorders such as autism.
Even though the importance of the Epigenome in psychology has been established, many in the emotional area are hesitant to accept its potential as a significant factor in mental illness. 1 reason for this is that it is difficult to define a real 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, even though the research 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 studying 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 now 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 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 talk about diseases of the brain which can be affected by Epigenetics.