An intelligence quotient, or IQ, is a score derived from one of several different standardized tests designed to assess intelligence. The term "IQ" comes from the German Intelligenz-Quotient. When modern IQ tests are constructed, the mean (average) score within an age group is set to 100 and the standard deviation (SD) to 15. Today almost all IQ tests adhere to the assignment of 15 IQ points to each standard deviation, but this has not been the case historically. By construction, approximately 95% of the population scores within two SDs of the mean, i.e., has an IQ between 70 and 130.
IQ scores have been shown to be associated with such factors as morbidity and mortality, parental social status, and, to a substantial degree, parental IQ. While the heritability of IQ has been investigated for nearly a century, controversy remains regarding the significance of heritability estimates, and the mechanisms of inheritance are still a matter of some debate.So Download Now