Immune system or the use of immunosuppressive medication. In contrast, autoimmunity results from a hyperactive immune system attacking normal tissues as if they were foreign organisms. Common autoimmune diseases include Hashimoto's thyroiditis, rheumatoid arthritis, diabetes mellitus type 1, and systemic lupus erythematosus. Immunology covers the study of all aspects of the immune system. Immunology is a science that examines the structure and function of the immune system. It originates from medicine and early studies on the causes of immunity to disease. The earliest known reference to immunity was during the plague of Athens in 430 BC. Thucydides noted that people who had
Behavioral immune system disease transmission. For instance, when the potential threat of disease is made salient, people tend to be less extraverted or sociable. Evidence suggests that the behavioral immune system also incorporates mechanisms designed to search out and process (heuristic) signs of disease at the level of basic visual attention. The behavioral immune system also has consequences at a cultural level of analysis. Under ecological circumstances in which diseases are more prevalent, people also tend to display more reticent and socially restricted forms of behavior, and human cultures are defined by more conservative norms and value systems. Some research suggests that the