(2005) stated that it is only through this understanding that human development and behaviors or behavioral disorders can be comprehended. Epigenetics is defined as the manner in which biological factors and experience interact to enhance adaptation and enfophenotypes are road markers that note biological origins of the development of human beings. Thus, these authors focused on adaptation as the key to understanding human development. Adaptation of the species, populations, and individuals takes place and can be measured over generations. This process includes genotypes or DNA that are changed through mutation that follows natural selection and adaptation. Genetic diversity is a demonstration of the differences found in people that are related to heritable skill sets that developed to meet unique challenges in the environment. This view is supported by the notion that human beings have evolved form an agrarian existence to an industrial one.
Research findings provide alternate views but tend to support the notion that biology, genes, and the environment interact in human development. Richardson and Norgate (2006) presented findings of IQ studies that show biology to be a stronger indication of outcomes than the environment. These authors stated that adoption studies show a pattern of parent-child correlations that support the genetic view that IQ affects outcomes more than the environment. For example, studies show that IQs of adopted children consistently correlate to a higher degree with the biological mother compared to the adoptive mother or father. However, these authors also stated that there are methodological considerations in these studies that may have affected results. Early studies assumed that the adoption situation represented a randomized effects design when in fact, numerous factors can affect these patterns that were not considered in the studies. Richardson and Norgate also noted that the earli...