Likewise, epigenetics (the study of heritable changes in gene function that occur without altering the DNA sequence) has reshaped the old nature-versus-nurture debate by highlighting the multi-dimensional character of the relationship between biological and social development. The growing understanding of transgenerational epigenetic modifications, whether nutritional or neurological, has opened new perspectives on the plasticity of the phenotype (an organism’s observable characteristics), and the factors that might affect it.