Xref: utzoo comp.ai:7985 sci.psychology:3582 alt.cyberpunk:4971 Path: utzoo!utgpu!cs.utexas.edu!samsung!usc!apple!portal!cup.portal.com!mmm From: mmm@cup.portal.com (Mark Robert Thorson) Newsgroups: comp.ai,sci.psychology,alt.cyberpunk Subject: Fluid vs. Crystallized Intelligence Message-ID: <35870@cup.portal.com> Date: 12 Nov 90 05:22:52 GMT Organization: The Portal System (TM) Lines: 160 I'm not in the AI field -- so I could be all wrong about this -- but it seems like the "fluid and crystallized intelligence" meme hasn't yet made the jump from the IQ- testing folks to the AI community. I'll try to correct that situation in this posting, then go on to make wild speculations about the underlying mechanisms represented by these important concepts. Our story begins with factor analysis, a powerful and controversial statistical technique. It is a technique for determining the minimum set of sources of variance that can account for the variance observed in a body of data, such as IQ test scores. The most significant discovery to emerge from factor analysis of IQ test data is that there are two types of intelligence, for which Catell [1] coined the widely-accepted terms "fluid" and "crystallized". Crystallized intelligence consists of acquired skills and draws upon learned knowledge. Examples of tests with a high correlation to crystallized intelligence are vocabulary tests, math tests, etc. Fluid intelligence is marked by problem-solving and the perception of relationships. Tests with a high correlation to fluid intelligence include predicting the next element of a series of numbers or figures, spatial visualization, and word analogies. When the two factors are separated, it can be seen that scores on tests for fluid intelligence track together as a group, indicating a single quantity is being represented. Likewise, tests weighted toward crystallized intelligence track together as a separate not-quite-independent group. (Critics point out this is the inevitable result of using factor analysis to define your groups, but the existence of these factors has been confirmed by experimental data.) A person high in fluid intelligence is also likely to be high in crystallized intelligence, but this is not always the case. It appears that a person's fluid intelligence can be spent on things -- such as athletics or art -- which are forms of crystallized intelligence not measured by IQ tests. Tests of crystallized intelligence show a gradual increase from birth to old age, with a decline in the rate of increase during the teenage years. Tests of fluid intelligence show a peaking in the late teens or early twenties, with a gradual decline that accelerates around age 55 or 60. Although IQ tests can't show whether fluid intelligence becomes crystalline intelligence, that is my opinion as illustrated below. * - * * * - * - * * * | | | | | | | * - * - * - * - * * - * - * - * - * | | | | | | * * - * * * - * - * - * | | | | | * - * - * - * - * * - * - * - * - * | | | | | | * * - * * - * * * - * | | * * * * * * * * * * * * The upper part of the diagram represents a crystallized network of agents. The bottom part represents fluid intelligence, which I speculate are a pool of uncommitted agents. These pools exist in every mental organ of consciousness. Crystallization occurs when a fluid agent is recruited into the network. This occurs whenever you have a new thought. It can be a temporary recruitment such as deciding to have a drink of water, or it can be a permanent recruitment like deciding not to smoke tobacco. Temporary agents return to the pool soon after they become obsolete, because lack of use softens their connections. The permanent agents tend not to return to the pool either because frequent use (i.e. interrogation from the network caused by re-thinking the thought) hardens their connections, or because the development of additional connections binds them more tightly to the network, or because they become buried in the network by the recruitment of subsequent agents. Occasionally defects, such as folds or bifurcations, occur in the pattern of growth of the network, as shown below. ************* ************* *********** ************* *********** ************* *********** *********** ********* *********** ********* ***** ***** ******* **** **** ***** **** **** * ** ** Normal Bifurcated This can be a benign occurrence, as in the case of the development of the language organ in bilingual people. Some agents are common to both languages, but there are two distinct subpopulations or lobes of language- specific agents. The agents in these lobes mostly have connections among themselves and to the common base, rather than to the other lobe. This can also be a dysfunctional condition, resulting from a trauma at a critical period during development and resulting in a mental disease such as -- in the extreme case -- multiple personality disorder. Each lobe of the bifurcation becomes a separate and competing suborgan, reinforcing its own connections and exacerbating the problem. This perhaps explains why electroconvulsive therapy (ECT) needs to be given in several rounds over a period of weeks to be effective. Each round peels back another layer of crystallized intelligence and makes the layer below it more vunerable to the next round. Eventually the root of the bifurcation is reached, and the network can be allowed to re-form or re-grow or re-organize or anneal, as shown below. ************* ************* ************* ************* *********** *********** ************* *********** *********** *********** ********* *********** *********** --> ***** --> ********* ***** ***** ********* **** **** ******* **** **** ***** ** ** * Before ECT After ECT Months later Why is the distinction between fluid and crystallized intelligence important? I believe you cannot have consciousness without having both. If you only have crystallized intelligence, you merely have a clockwork mechanism. Such a mechanism could re-think old thoughts, but it could not have any new thoughts. It is the having of new thoughts -- through the conversion of individual particles of fluid intelligence into a network of crystallized intelligence -- which is consciousness. ------------------ [1] Catell, Raymond B., "Theory of fluid and crystalized intelligence: A critical experiment", Journal of Educational Psychology, 1963, 54, 1-22.