In intelligence, is heredity or environment more important?
During the 20th century, the answer to the above concern would have been that genetic factors were essential. This was the dominant position in most approaches, and this conclusion stemmed from the belief that intelligence was stable over time and that whoever was born intelligent remained intelligent. This conclusion cannot be completely abandoned, but it can be reformulated.
It is true that human beings think with their brains, and therefore, the number of neurons, the connections between them, the speed of transmission, among other factors, are genetically determined and are especially influenced by the nutrition received in early life. However, there is increasing evidence of the extremely high levels of modifiability and plasticity of the human brain.
Various studies in the last two decades have shown that intellectual abilities are more variable than predicted during the 20th century. This necessarily means that the environment plays a more important role in determining intelligence and exceptionality than predicted during the previous century.
As widely developed by the Historical-Cultural School,1 cognitive, evaluative, and praxiological processes are demarcated by the historical and cultural contexts in which individuals live. “We are,” as Merani would say, “historically and culturally determined beings. Thus, individuals exist by birth, we remain historically present for a period of time, and we realize our being in the sociocultural circumstances in which we live” (Merani, 1976).
Consequently, parents and teachers are essential factors in detecting children's abilities, talents, motivations, and potential in a timely manner. Likewise, we are jointly responsible for whether these potentialities develop or not. Without parents and teachers, there is no detection of potentialities, and without mediation, there is no development, as Feuerstein dramatically demonstrated when he saw how abilities deteriorated in the absence of quality cultural mediators for Jewish children and youth before and during the Second World War (De Zubiría, 2002).
This implies that analytical, evaluative, and practical intelligence are highly variable, and that high or low levels in each of the intelligences will depend fundamentally on teachers and parents.
To go deeper: Myths about intelligence and talent