The question of whether a person's character can be predicted from their DNA remains one of the most debated topics at the intersection of genetics, psychology, and parenting practice. In a recent interview with RBC-Ukraine, geneticist Dmytro Mykytenko gave a detailed answer: no single "personality gene" exists in nature, yet genetics does set certain boundaries within which personality develops. According to him, features of the nervous system's functioning — reactivity, plasticity, and a tendency toward certain habits — can be inherited. These biological predispositions, combined with upbringing, environment, and life experience, shape what we call character.
The Polygenic Nature of Character and Estimating Genetic Contribution
Mykytenko emphasizes that character has a polygenic component: it is influenced not by one or two genes, but by the complex interaction of many loci. According to the specialist's estimates, the genetic contribution to the formation of character is roughly 40–60%. This means that even with a high hereditary predisposition, the remaining portion — 40 to 60% — is determined by environmental factors. Thus, DNA sets not a sentence, but a probabilistic "corridor" of possibilities within which a person develops under the influence of external circumstances.
Identical Twins: A Clear Illustration of the Role of Environment
To make the point clear, the geneticist gave the example of identical twins. Even with a virtually identical genetic makeup and similar living conditions, two people can develop along entirely different trajectories. Mykytenko describes a hypothetical situation: one twin falls off a bicycle and suffers a concussion, while the other has no such experience. This single event can alter the further development of the nervous system and, as a result, behavioral patterns. Over time, the accumulation of differences in environment and experience makes even genetically identical people increasingly dissimilar to one another.
Genetic Risk Does Not Mean Inevitability
An important point Mykytenko draws from his interview: having a genetic predisposition to a certain condition does not guarantee that it will manifest. As an example, he cites attention deficit hyperactivity disorder (ADHD). A high genetic predisposition to this disorder does exist, however, but its actual manifestation can be influenced by stress, birth trauma, or metabolic disorders. At the same time, the specialist notes that such manifestations can and should be addressed: whether a genetic risk is realized depends not only on heredity but also on upbringing, lifestyle, and accumulated life experience.
What Genetic Tests Actually Show
Against the backdrop of the growing popularity of commercial DNA tests that promise to "decode character" or "predict destiny," the geneticist's position sounds like a sober reminder: no existing test can determine a person's character from a set of genes. Tests can identify individual predisposition markers, but interpreting them in isolation from context — upbringing, environment, nutrition, and life events — is incorrect. Genetics provides information about probabilities, not a ready-made life script. That is precisely why, according to Mykytenko, even people with very similar genetic makeups can become entirely different personalities.
