Читать книгу Abnormal Psychology - William J. Ray - Страница 56

Another big idea that emerged in the 1800s was that all of nature is in constant flow and that things, including organisms, change. This idea focused on the evolution of species and is most often associated with the work of Charles Darwin (1809–1882). Variation was to become one of the major components of Darwin’s thinking concerning evolution. In fact, he began his thinking with the assumption that heritable variations can and do occur in nature. Darwin then presented the important realization that not all plants or animals that come into existence survive. Many organisms such as sea stars, for example, produce millions of eggs of which only a limited number survive. Depending on climate conditions, food supply, predator population, and a host of other factors including disease, only a limited number of births survive to maturity.

hierarchical integration: through inhibitory control, the various levels of the brain, such as the brain stem, the limbic system, and the neocortex, are able to interact with each other, and higher levels restrict or inhibit the lower levels

variation: the assumption that heritable variations can and do occur in nature

natural selection: Darwin’s idea that if an organism has even slight variations that help it to compete successfully for survival, then over time the species will be made up more of members with these characteristics and less of individuals lacking these features

sexual selection: the manner in which males and females choose a mate

Consequently, Darwin (1859) suggested, “There is a frequently recurring struggle for existence.” Who is to survive in this struggle? Darwin suggested that if an individual has even a slight variation that helps it to compete successfully for survival, then over time the species will be made up more and more of members with these characteristics and less and less of individuals lacking these features. This process is referred to as natural selection. Darwin described this process in his 1859 book, On the Origin of Species by Means of Natural Selection.

Darwin later extended the theory of natural selection to include sexual selection, or the manner in which males and females choose a mate. This work is described in his 1871 book, The Descent of Man. Darwin noted that males and females differ not only in terms of organs of sexual reproduction but also in secondary sexual characteristics such as mammary glands for the nourishment of infants in females or facial hair in males. According to Darwin, sexual selection depends on the success of certain individuals over others of the same sex. Darwin also saw that besides same-sex competition, there is also competition to attract members of the opposite sex. As you can imagine, there has been continuous debate and research concerning what attraction means for males and females.

Darwin began the Origin work with the question of natural selection especially as it related to animals. In The Descent of Man, he expanded these ideas to humans and also examined the question of sexual selection. In other works, such as his notebooks, he extended his research to cognitive and emotional processes. The broad question is that of how psychological functions have evolved. One answer he gives is that living in social groups produces an increase in cognitive ability. Darwin also presents notes on memory and habit, imagination, language, aesthetic feelings, emotion, motivation, animal intelligence, psychopathology, and dreaming (Gruber, 1974). One important question is the manner in which self-preservation, sexual selection, and social processes are reflected in psychopathology.