Cattell and Horn distilled global intelligence (G) into two principal components: (1) fluid intelligence or Gf; and (2) crystallized intelligence or Gc. Fluid intelligence is largely innate and represents someone’s ability to solve novel problems and can therefore be liked to raw processing power or the brain. Fluid intelligence is typically associated with the right hemisphere of the brain (i.e. simultaneous processing). Fluid intelligence peaks in our mid 20s and declines thereafter.
Crystallised intelligence, on the other hand, is associated with the body of knowledge learned in school and through formal education. People with greater schooling will on average have a much higher Gc than those people who have limited formal schooling. Because crystallized intelligence is akin to an accumulated body of knowledge, it is not surprising that Gc peaks in our mid 50s, and begins a slow decline thereafter. Crystallized intelligence is linked to the left hemisphere of the brain (sequential processing).
Most professionally administered tests will be able to measure both types of intelligence. However, different questions and/or tests can be used to measure each type of intelligence. Similarly, in the world of online IQ testing, some tests will be better designed for measuring either Gf or Gc.
From an online testing standpoint (where your audience is global), it would be impossible design a scientific test for Gc that does not suffer from cultural bias – that is, it is not possible to design a culture-fair IQ test for crystallized intelligence when you are testing a global audience. In fact, anything that tests a body of knowledge may favor some groups over others. For instance, a test which asks: “who was the third president of the United States” (Thomas Jefferson is the answer by the way), is a question which is more likely to be answered correctly by American test takers than say, Nigerian test takers. And even then, American history majors may be at a significant advantage in getting this answer right than say, American Psychology majors.
Word definitions or describing certain concepts, also suffers from cultural bias due not only to language fluency problems (i.e. should we be ascertaining French-speakers with questions written in English? Of course not), but also due to the fact that different countries and languages use words in different ways. (e.g. in English, you can say “I love pizza”. But you cannot say “Yo amo Pizza” in Spanish, instead, you would say, “A mi me gusta la pizza”, which essentially means that you like pizza). So a crystallized intelligence test cannot be a culture-fair IQ test.
A Culture-fair IQ test for a global audience
For this reason, fluid intelligence tests are the only types of IQ tests that can be described as ‘culture-fair IQ tests’. Fluid reasoning tests such as our iq-brain.com test, Raven’s Progressive Matrices (RPM) or Cattell Culture-fair IIIa tests are based on reasonably abstract picture sequences and missing patterns. It can perhaps be argued that knowledge of geometry (or lack thereof) can induce a cultural bias, but it remains that a triangle is a triangle (3 sides, and internal angles totaling 180 degrees) in every nation on earth.
When it comes to testing the IQ of a global internet audience, a culture-fair IQ test is the only kind of test which has scientific merit to ascribe rankings between different nations (i.e. you can administer the exact same test to everyone, with only the instructions requiring translation), and the only types of culture-fair IQ tests that exist will test Fluid intelligence (Gf), which includes Visual Processing ability (Gv), Processing Speed (Gs) and Working Memory (Gsm). Gv, Gs and Gsm are all sub components of fluid intelligence.
Take our culture-faire IQ test HERE.