What is intelligence?

Intelligence is best understood as a broad term for the ability to "adapt to, shape, and select environments."[1]  It is generally used as a measure for cognitive ability in humans, animals and sometimes machines. 

Computational Theory of the Mind

According to the MIT Encyclopedia of Cognitive Science, the Computational Theory of the Mind or CTM states that the mind is a "digital computer" that "stores symbolic representations and manipulates them according to syntactic rules; that thoughts are mental representations—more specifically, symbolic representations in a LANGUAGE OF THOUGHT; and that mental processes are causal sequences driven by the syntactic, but not the semantic, properties of the symbols."[2]

In this theory, mental thoughts are simple representations of what the brain is really doing everytime you think or do something.  Under the computational theory of the mind, the brain will literally be going through a serious of computations, algorithms and subroutines in order to produce the desired output.[3]

Before the modeling of neural networks began, CTM was also considered to be the "only game in town" as far as cognitive theories of the mind were concerned.  As such, it became a major vehicle for the hope of producing artificial intelligence.  If the mind is just a "digital computer" where algorithms are running to create intelligence and thoughts, then similar algorithms could be developed that would create an artificial intelligence.  As a result, some now consider CTM to be a theory of "good old fashioned artificial intelligence."  At the very least, those who argue for the case of CTM must now make cases that show how their ideas about the CTM model show a more realistic representation of the human mind the network models.[4]

Turing's Test for Intelligence

In "Computing Machinery and Intelligence," A.M. Turing proposes a thought experiment to show that machines can display qualities of intelligence that would match those of a human being.  It would later become known as the Turing Test for Intelligence and goes as follows:

It begins with three people: a man (A), a woman (B), and a moderator (C) who can be of either gender.  The moderator is in a separate room from the man and woman.  It is the moderator's job to ask each person, known only as X and Y to the moderator, questions which will help the moderator figure out the sexes of X and Y.  The questions will be answered via a typewriter or some equivalent in order not to taint the results.  Any question may be asked that will help the moderator determine the genders of X and Y.  However, X is going to lie when asked questions in an attempt to fool the moderator and Y is going to tell the truth (or vice versa).  Now, what if a machine replaces A in the game and the moderator answers wrongly just as often as he or she did when A was a man and not a machine?[5]

It is here where Turing believes a machine can properly be said to display intelligence equivalent to that of a human.  If the moderator is unable to distinguish between a machine who is answering the questions and a man or woman who is answering the questions, then the machine has passed the Turing Test for Intelligence.  A machine that passes this test would technically need the ability to use natural language, to reason, and to understand and interpret what is being said to the machine in order to produce a response.

Criticisms

One of the major arguments against the Turing Test as a measure of human intelligence in a machine is presented by John Searle in the form of the "Chinese Room Argument."

Chinese Room Argument

 In "Minds, Brains, Programs" Searle (1980) proposes the Chinese Room Argument as an argument against the notion that a machine would be considered to have intelligence if it passes a Turing-like Test.

Searle lays out the Chinese Room argument as follows:

 Suppose one is locked in a room by oneself.  This person is given a list of Chinese symbols and knows no Chinese at all.  Then this person is given a second list of Chinese symbols with a set of rules for relating the second list to the first and these rules are written in English.  A third list of Chinese symbols is given with English rules that correllate to the first two lists.  This third list tells one which Chinese symbols to put together in response to certain Chinese symbols.  Unbeknownst to the person in this room, the first list would be considered a "script,"  the second list a "story," and the third are "questions."  What the person in the room does not realize is that they are being given questions in Chinese to which they must answer those questions back in Chinese in a certain way.[6]

With this thought experiment which Searle makes as an analogy to the Turing Test, Searle is able to show that there is a distinct difference between an intelligent machine that passes the Turing Test and intelligent human.  Searle asks, if a machine passes the Turing Test, does it have any understanding of what it is spitting out as answers?  Searle would say no because that machine has no intentionality behind its actions.  Just as the human who does not understand Chinese has no idea what he is really doing as he follows the rules blindly in the room, a machine that passes the Turing Test is also following programmed rules in order to answer each question without really understanding or cognizing what is being said to it or what it is saying.[7]

Real World Implications

As examples such as the Turing Test become more widely use as tests for intelligence which are equivalent to humans, the issue of rights for such machines or beings will be raised.  In Justin Leiber's dialogue, Can Animals and Machines Be Persons?, this sort of question is raised.  If there are animals or machines who display more intelligence than many humans, can these machines or animals be considered persons?  If so, do they have rights as persons?  If not, do they still garner rights for their intellects which, at times, may rival that of humans?  These types of questions can only become more recurrent as the intellect of machines grows and we see computers with intellects similar to that of "AL" appear with apparent wants and desires.[8]

References

[1] "Intelligence" MIT Encyclopedia of Cognitive Science, Cambridge, MA: MIT Press, 1999.

[2] "Computational Theory of Mind" MIT Encyclopedia of Cognitive Science, Cambridge, MA: MIT Press, 1999.

[3] "Computational Theory of Mind" MIT Encyclopedia of Cognitive Science, Cambridge, MA: MIT Press, 1999.

[4]  Horst, Steven, "The Computational Theory of Mind", The Stanford Encyclopedia of Philosophy (Fall 2005 Edition), Edward N. Zalta (ed.), URL = <http://plato.stanford.edu/archives/fall2005/entries/computational-mind/>

[5] Turing, A. M. (1950) "Computing Machinery and Intelligence," Mind 59, pp. 433-460.

[6] Searle, J. (1980) "Minds, Brains, Programs," Behavioral and Brain Sciences, 3: 417-424.

[7] Searle, J. (1980) "Minds, Brains, Programs," Behavioral and Brain Sciences, 3: 417-424.

[8] Leiber, Justin (1985) Can Animals and Machines be Persons? A Dialogue. Hackett Publishing.

Further Reading

• "Chinese Room Argument" MIT Encyclopedia of Cognitive Science, Cambridge, MA: MIT Press, 1999.
• "Computational Theory of Mind" MIT Encyclopedia of Cognitive Science, Cambridge, MA: MIT Press, 1999.
• "Intelligence" MIT Encyclopedia of Cognitive Science, Cambridge, MA: MIT Press, 1999.
• Ashby, W. R. (1952) "Can a Mechanical Chess-player Outplay its Designer?," British Journal for the Philosophy of Science, 3(9), pp. 44-57.
• Leiber, Justin (1985) Can Animals and Machines be Persons? A Dialogue. Hackett Publishing.
• Searle, J. (1980) "Minds, Brains, Programs," Behavioral and Brain Sciences, 3: 417-424.
• Turing, A. M. (1950) "Computing Machinery and Intelligence," Mind 59, pp. 433-460.
• Horst, Steven, "The Computational Theory of Mind", The Stanford Encyclopedia of Philosophy (Fall 2005 Edition), Edward N. Zalta (ed.)

External Links

• Intelligence News
• Steven Pinker on the Computational Theory of the Mind
• The Turing Digital Archive
• Encyclopedia of Computational Intelligence
• Turing Test for Lethal Robots
• John Searle on Dualism