The nature versus nurture debate is one of the oldest and most controversial debates in psychology. The debate centers on the relative contributions of genetic and environmental factors to individual behavior. The nature side of the debate argues that genes—just like those you might find in a DNA app—are the primary determinant of behavior, while the nurture side of the debate argues that the environment is the primary determinant of behavior.

Whether you’re studying for a special education master’s degree or you’re simply interested in genetic diversity and its impact on your family tree, read on to learn more about nature and nurture as it applies to ancestry.

Nature vs. Nurture in a Scientific Context

 

The nature versus nurture debate has been around for centuries, but it was not until the early 1800s that it was first discussed in a scientific context. In 1809, French naturalist Jean-Baptiste Lamarck published a book entitled Philosophie Zoologique, in which he proposed the theory of acquired characteristics. Lamarck argued that organisms could inherit the traits that they acquired during their lifetime. For example, if an individual exercised its muscles, the individual would be more likely to pass on the trait of muscular strength to its offspring.

The theory of acquired characteristics was opposed by English naturalist Charles Darwin, who published his theory of evolution by natural selection in 1859. Darwin argued that the traits of an organism were determined by its genes, and that the environment played no role in shaping behavior.

In the 1920s, American psychologists Edward Thorndike and John B. Watson debated the role of genes and environment in shaping behavior. Thorndike argued that genes were the primary determinant of behavior, while Watson argued that the environment was the primary determinant of behavior.

The nature versus nurture debate was revived in the 1960s, when British developmental psychologist John Bowlby argued that the environment was the primary determinant of behavior, while American psychologist B. F. Skinner argued that the environment played only a minor role in shaping behavior.

An In-Depth Look at DNA

 

The nature versus nurture debate is still unresolved, but research over the past few decades has provided evidence that both genes and environment play a role in shaping behavior. The genetic contribution to behavior is called heritability, and the environmental contribution to behavior is called epigenetics.

Heritability is the proportion of variation in a trait that is due to genetic variation. Epigenetics is the study of how environmental factors can influence the expression of genes. Epigenetic research has shown that the environment can influence the expression of genes in two ways: by altering the structure of DNA, and by altering the way that genes are expressed.

Epigenetic research has shown that the environment can influence the expression of genes in two ways: by altering the structure of DNA, and by altering the way that genes are expressed.

The structure of DNA is altered by DNA methylation, which is the addition of a methyl group to DNA. DNA methylation can silence the expression of genes, and it can also cause genes to be expressed in a different way.

The way that genes are expressed is regulated by epigenetic marks, which are chemical modifications of histones. Histones are proteins that form the structure of DNA. Epigenetic marks can cause genes to be expressed in a different way, or they can cause genes to be silenced.

Epigenetic marks can also be removed from histones. One way that epigenetic marks can be removed is by demethylation, which is the removal of a methyl group from histones. Demethylation can activate genes by making the histones more flexible, which allows the transcription factors to bind to the gene. Another way that epigenetic marks can be removed is by deacetylation, which is the removal of an acetyl group from histones. Deacetylation can silence genes by making the histones more rigid, which prevents the transcription factors from binding to the gene.

The role of genes in behavior is still being studied, but the role of the environment is becoming increasingly clear. The environment plays a role in shaping behavior by influencing the expression of genes, and by shaping the development of the brain.