The concept of “nature and nurture” is used to distinguish between genetic and environmental influences on the formation of individual, mainly behavioral, traits. Different approaches that interpret nature and nurture as completely opposite or complementary aspects of human development have been discussed for decades. The paper addresses the most important points of nature vs nurture debate from the perspective of biological research, especially in the light of the recent findings in the field of epigenetics. The most important biological concepts, such as the trait, phenotype and genotype, as well as the evolution of other crucial notions are presented. Various attempts to find the main source of human variation are discussed - mainly the search for structural variants and the genome-wide association studies (GWAS). A new approach resulting from the discovery of “missing heritability”, as well as the current knowledge about the possible influence of epigenetic mechanisms on human traits are analyzed. Finally, the impact of epigenetic revolution on the society (public attitude, health policy, human rights etc.) is discussed.