# Chapter 13: Etiquette in our genes

"For behaviour, men learn it, as they take diseases, one of another."

The author of the quote, the English statesman and philosopher Francis Bacon, described a phenomenon that we commonly observe in the course of our lives. Children's behaviour often reflects the behaviour of their parents, siblings or other members of society (you can find an example of such learned behaviour in Chapter 2 – How does a scientist work), but genetic predisposition also plays a role here. But which of these factors is decisive?

The answer lies somewhere in the middle. In general, we can say that the resulting phenotype of an individual is influenced by its genes and at the same time by the environment. The same applies in this case. The influence of genes on the behaviour of an organism is studied by the scientific field of behavioural genetics. Its founder is Francis Galton, cousin of the famous Charles Darwin. Galton lived in the 19th Century and was a polymath, which means that he was involved in practically all branches of science at the same time. In one of his observations, Galton dealt with the heredity of human abilities and mental qualities. He analysed the family trees of the English nobility, focusing on the social and intellectual achievements of individual members. He published the results in the book "Hereditary Genius" in 1869, exactly 10 years after Charles Darwin published the book "The Origin of Species". In his results, Galton outlined the possible influence of the environment on the exceptionality of individuals of the English nobility. Although he interpreted his results vaguely and spoke only of a possible influence, his study started a debate about the role of genes and environment in shaping behavior. Within the field of behavioural genetics, several model organisms are used in research. Sometimes they are unicellular microorganisms, other times insects or multicellular vertebrates - most often mice or rats, for which there is a very well-developed system of studying various forms of behaviour.