In response to an unknown trigger, the immune system may begin producing antibodies that instead of fighting infections, attack the body's own tissues. Treatment for autoimmune diseases generally focuses on reducing immune system activity.
What's taught in school. Some of the items in standardized achievement tests measure the knowledge or skills that students learn in school. In certain subject areas, such as mathematics, children learn in school most of what they know about a subject.
With standardized IQ tests, IQ tests are designed so that their scores have a âbell curveâ distribution in the general population with an average of 100. This curve has a peak in the middle where most people score and tapering ends where only a small percentage of people score.