Probabilistic epigenesis is a way of understanding human behavior based on the relationship between experience and biology. It is a variant form of epigenetics, proposed by American psychologist Gilbert Gottlieb in 1991. Gottlieb’s model is based on Conrad H. Waddington's idea of developmental epigenesis. Both theories examine the complexity of the ways in which the brain develops and explore factors that occur outside the genome. However, probabilistic epigenesis differs from Waddington’s model as it relies much more heavily on the potential developmental impacts of experience and environment and how they interact with an individual’s genes. Probabilistic epigenesis takes into account developmental, hormonal, environmental, neuropsychological, and genetic factors in order to explain various forms of behavior. In developmental psychology In developmental psychology, probabilistic epigenesis is a theory of human behavior that assumes that different neural structures develop and activate either based on an individual's biology or interactions with their environment. It relies on the idea that there are multi-directional interactions between biological and psychological factors, meaning probabilistic epigenesis is a non-hierarchical model of understanding development. The biological factors, also known as genetic determinants, involve an individual's genetic makeup, and how it influences their behavior. These factors must be looked at alongside environment variables, however, as the number of genes in a human brain is insufficient in regards to explaining all aspects of the human mind–there is simply not enough storage. According to the theory of probabilistic epigenesis, the environment (socioeconomic, household, etc.) in which a person lives and interacts with contributes to overall behavioral development by triggering certain genetic information to activate. Socioeconomic environment The relationship between socioeconomically disadvantaged youth and poor physical health is a topic notably evaluated by James Hamblin. Research has proven there is a correlation between disadvantaged youth and high blood pressure, excess body fat, and high levels of cortisol. The pressures associated with a low socioeconomic background have proven to produce chronic stress in individuals who strive for upward mobility, likely due to the increased familial and social pressures. Subsequently, chronic stress has been linked to a break down in bodily functions, and is thus a stimulant for disease. In other words, this means that the extrinsic factor of socioeconomic class can cause an individual to be less physically capable of handling stress and heavy workloads than someone born into a wealthier environment. This means that their self-control and work ethic comes with the price of