What do IQ tests determine?

Are IQ tests reliable?

• Some of the more common types of IQ tests are: http://www.indiana.edu/~intell/intelligenceTests.shtml#history There have been many IQ tests used over the years, and many different proposed scales to evaluate the results. Many tests have been revised and edited in attempts to provide more accurate results. http://www.indiana.edu/~intell/intelligenceTests.shtml#history of this can be found http://psychology.about.com/od/psychologicaltesting/a/int-history.htm. There is, of course, some criticism surrounding the reliabilty of IQ tests... There are sites like http://iq-test.learninginfo.org/iq02.htm which quote sources such as Walter Lippmann who said that "We cannot measure intelligence when we have not defined it" http://historymatters.gmu.edu/d/5172/ There are other http://www.ncbi.nlm.nih.gov/pubmed/21518867 which suggest that the outcome of an individual IQ test is largely dependent on the motivation of the person taking it. Or at least that individual motivation to succeed introduces a variable into the evaluation process which is not accounted for by those determining results. The http://www.infed.org/thinkers/gardner.htm seems to assert that there are levels of intelligence which are not measured by standardized IQ tests. Howard Garder is quoted as saying: In the heyday of the psychometric and behaviorist eras, it was generally believed that intelligence was a single entity that was inherited; and that human beings - initially a blank slate - could be trained to learn anything, provided that it was presented in an appropriate way. Nowadays an increasing number of researchers believe precisely the opposite; that there exists a multitude of intelligences, quite independent of each other; that each intelligence has its own strengths and constraints; that the mind is far from unencumbered at birth; and that it is unexpectedly difficult to teach things that go against early 'naive' theories of that challenge the natural lines of force within an intelligence and its matching domains. (Gardner 1993: xxiii) Has the term "intelligence" been defined well enough that it can be objectively measured? If so, do IQ tests reliably determine an individual's intelligence? Or are they too subjective to be considered accurate? Is there scientific evidence to support claims of being able to accurately assess individual intelligence as related to real-world outcome. Or are IQ tests at best a ballpark estimate of individual intelligence?

• Answer:

  Good Summary: A good summary of the literature on Intelligence can be found in the article "Intelligence: Knowns and Unknowns" http://socrates.berkeley.edu/~maccoun/PP279_Neisser1.pdf. You will find references for the claims I make below and further discussion. It was based on an American Psychological Association Task Force and represents propositions that received "unanimous support of the entire Task Force". It addresses each of your questions. Below are just some general observations regarding your points. Has the term "intelligence" been defined well enough that it can be objectively measured? This is open to debate. There are competing definitions. Good intelligence tests certainly measure something. And that which is measured is one of the best predictors of education outcomes, and work performance, and is also a good predictor of many other important outcomes. If so, do IQ tests reliably determine an individual's intelligence? IQ tests are reliable in that longitudinal studies have shown that test scores are very stable over long periods of time. Thus, there is good evidence that what is measured is a trait. IQ tests do not determine "intelligence"; theory would suggest that some factor in the individual determines test scores. Whether you label this factor "intelligence", depends on definitions and is open to debate. Or are they too subjective to be considered accurate? Intelligence tests are not a subjective measure, in that the score derived from an intelligence test is generally objectively determined by standardised scoring processes. Deciding what intelligence test scores truly mean is still an open question. However, plenty of research has explored the correlates Is there scientific evidence to support claims of accuracy? What do you mean by "accuracy"? There is plenty of evidence that Intelligence tests are useful in predicting important real-world outcomes. Or are IQ tests at best a ballpark estimate? Estimate of what?