New Theory Claims that Identity Resides in the Human Genome and is Compatible with Cognitive Perspectives of ‘Self’

Newswise — One of the greatest philosophical thought exercises that has challenged the concept of identity, is the Ship of Theseus paradox. It poses the question: Are we the same person over time? The original meaning of ‘Identity’ is derived from Medieval Latin identitas or idem meaning ‘sameness’ or ‘same’. But ‘sameness’ has been difficult to comprehend.

The ancient Greek paradox of Theseus’ ship illustrates the conundrum. As time passed its planks had to be changed one by one when they began to rot. At what point, philosophers asked, did the original ship cease to be itself? We know that the chemical constituents of our bodies are continually changing. As such, are we the same person as we move through time?   

A recent article entitled Taking Account of Human Genetics in Identity Research, which was published in the Journal of Genetic Genealogy (JoGG) puts forward a compelling theory about the role that genetics plays in identity. Despite total cell and chemical replacement throughout the lifetime of the individual, this differs in many ways compared to the components of a non-living thing like a boat. 

Personal Identity  

The author of the article Raymond M. Keogh, who is a biological research scientist, family historian and director of Our Own Identity, points out that DNA is not an indifferent chemical molecule. It is highly dynamic, governs biology across the entire scale of life, actively contributes to all living processes and contains the instructions needed for an organism to develop, survive, thrive, reproduce, and pass on genetic information from one generation to the next. It is also known that DNA influences personal attributes. Most psychological traits and all major psychiatric disorders have been shown to be influenced by the human biome. DNA (nature) also ameliorates the impacts of environmental factors (nurture) to give the organism the best chance to stay alive and prosper.  

Since 1987, thousands of forensic cases have been decided with the assistance of genetic fingerprinting. This has been based on observations, which indicated that the nuclear DNA of every cell remains the same throughout the life of the organism. If so, it would mean that science reveals what is meant by ‘sameness’ in biological terms in who we are. However, as DNA sequencing techniques are improving, an increasing number of anomalies are being recorded as, for example, in the case of post-zygotic mutations. Therefore, ‘sameness’ does not reside in all DNA sequences.   

However, it is pointed out that the individual’s genome conforms to a specific set of unchanging conditions. These include: 1. Continuity from its beginning, in terms of life processes or metabolism; 2. Viability in the sense that it survives as a single entity, which overcomes the suggestion that the chimera or mosaic genome is, in fact, two or more people in one; 3. Individuality in that it is singular at all times in expressing its nature; and 4. Uniqueness in that it is unlike any other genome. In other words, identity or ‘sameness’ is to be found in the nature of the human genome. This conclusion shows that we are the same person always.  

Communal Identity 

In addition to identity at the individual level, humanity has a communal dimension. The entire human genome is composed of unique and therefore different individual genomes. It follows that no subgroups—no matter how large or small—are made up of individuals who share a genetic ‘sameness’ that is exclusive to that cohort. Hence, DNA patterns do not correlate well with the normal divisions of humanity like race, ethnicity, culture, or nation. This means that communal identity is located exclusively at the level of the species, which is composed of all living individuals or personal genomes. The nature of the characteristics that imbue the individual with personal identity (i.e., continuity, viability, individuality and uniqueness) are shared by all people and provides us with a basis for expressing communal identity or ‘sameness’ at the global level. 

In addition to providing an outline of personal and communal identity, the article deals with the objections that are commonly levelled against the notion of uniqueness in the personal genome, like the case of identical twins. Or the possibility of infringing distinctiveness where cloning might occur. And how do epigenetic changes affect ‘sameness’? What about the effects of fetomaternal microchimerism on one’s DNA? Another issue that is sometimes raised is the complexity of our microbiology which takes into consideration the relationships between the host and the microbiome especially in relation to symbiosis and pathogenesis. Are we not a composite of several species? All these apparent contradictions are shown not to infringe our biological identity.  

Uniting biology and cognitive perspectives 

The dichotomy between biological identity and the myriad of cognitive perspectives of ‘self’ are discussed. By recognizing that ‘sameness’ resides in our genome allows sociologists to advance with greater ease in new directions because they are unhindered by the need to reify identity from subject notions of self. The commonly felt gulf between biology and social perspectives is recognized but the conclusion is reached that studies in human genetics and cognition can be understood in ways that are compatible and complementary rather than irreconcilable or contradictory.   

Viewed from this vantage point, the potential exists to merge biological identity and cognitive perspectives of ‘self’, which will lead to a more comprehensive understanding of who we are and where we come from, with wider implications for reshaping our understanding of identity itself.