As the ratio of mental age (ma) to chronological age (ca) multiplied by 100 [thus, IQ = (ma/ca) x 100].
An intelligence quotient (IQ) is a score derived from one of several standardized tests designed to assess human intelligence. The abbreviation IQ was coined by the psychologist William Stern for the German term Intelligenz-quotient, his term for a scoring method for intelligence tests he advocated in a 1912 book. There are a variety of individually administered IQ tests in use in the English-speaking world. The most commonly used individual IQ test series is the Wechsler Adult Intelligence Scale for adults and the Wechsler Intelligence Scale for Children for school-age test-takers. The Stanford-Binet (SB) - the best and most popular intelligence test is a Cognitive ability assessment used to measure intelligence (IQ). The Stanford-Binet measures five factors of cognitive ability: Fluid Reasoning, Knowledge, Quantitative Reasoning, Visual-Spatial Processing, and Working Memory.  Description. The Stanford-Binet intelligence scale is a direct descendent of the Binet-Simon scale, the first intelligence scale created in 1905 by psychologist Alfred Binet and Dr. Theophilus Simon. The Stanford-Binet intelligence scale is used as a tool in school placement, in determining the presence of a learning disability or a developmental delay, and in tracking intellectual development. Intelligence quotient, or IQ, was originally defined as mental age divided as mental age divided by chronological age and multiplied by 100.  Intellectual functioning level is defined by standardized tests that measure the ability to reason in terms of mental age (intelligence quotient or IQ). Mental retardation is defined as IQ score below 70-75. Adaptive skills are the skills needed for daily life. Low IQ scores and limitations in adaptive skills are the hallmarks of mental retardation. Aggression, self-injury, and mood disorders are sometimes associated with the disability. The severity of the symptoms and the age at which they first appear depend on the cause. Psychologists have attempted to measure it for well over a century. Intelligence Quotient (IQ) is the score you get on an intelligence test. Originally, it was a quotient (a ratio): IQ= MA/CA x 100 [MA is mental age, CA is chronological age]. Today, scores are calibrated against norms of actual population scores. Intelligence is a person's capacity to (1) acquire knowledge (i.e. learn and understand), (2) apply knowledge (solve problems), and (3) engage in abstract reasoning. It is the power of one's intellect, and as such is clearly a very important aspect of one's overall well-being. intelligence quotient (IQ). defined originally as the ratio of mental age (ma) to chronological age (ca) multiplied by 100 [thus, IQ = (ma/ca) x 100]. On contemporary intelligence tests, the average performance for a given age is assigned a score of 100. Lewis M. Terman. Terman, a psychologist at Stanford University, was one of the first to create a version of the test for people in the United States, naming the localized version the Stanford–Binet Intelligence Scale (Fancher & Rutherford, 2012) (Becker, 2003). Stanford–Binet Intelligence Scale: Fifth Edition [edit]. Just as it was used when Binet first developed the IQ test, the Stanford–Binet Intelligence Scale: Fifth Edition (SB5) is still rooted in the schooling process to assess intelligence. It continuously and efficiently assesses all levels of ability in individuals with a broader range in age By this definition, approximately two-thirds of the population scores between IQ 85 and IQ 115, and about 5 percent of the population scores above 125. IQ scores have been shown to be associated with such factors as morbidity and mortality, parental social status, and, to a substantial degree, biological parental IQ. There are a variety of individually administered IQ tests in use in the English-speaking world. The most commonly used individual IQ test series is the Wechsler Adult Intelligence Scale for adults and the Wechsler Intelligence Scale for Children for school-age test-takers.
https://en.wikipedia.org/wiki/Intelligence_quotient https://www.stanfordbinet.net/ http://medical-dictionary.thefreedictionary.com/Stanford-Binet+Intelligence+Scales http://www.findtestanswers.com/view/13866/Intelligence-quotient-.html http://medical-dictionary.thefreedictionary.com/mental+retardation http://webspace.ship.edu/cgboer/intelligence.html https://quizlet.com/626314/chapter-11-myers-intelligence-flash-cards/ https://en.wikipedia.org/wiki/Stanford%E2%80%93Binet_Intelligence_Scales https://en.wikipedia.org/wiki/Intelligence_quotient
originally iq was defined as