Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!sol.ctr.columbia.edu!lll-winken!tristan!loren From: loren@tristan.llnl.gov (Loren Petrich) Newsgroups: comp.ai.neural-nets Subject: Re: Observations on the State of NN theory Message-ID: <66911@lll-winken.LLNL.GOV> Date: 23 Aug 90 05:43:53 GMT References: <3430010@hpwrce.HP.COM> Sender: usenet@lll-winken.LLNL.GOV Reply-To: loren@tristan.UUCP (Loren Petrich) Organization: Lawrence Livermore National Laboratory Lines: 57 In article <3430010@hpwrce.HP.COM> kingsley@hpwrce.HP.COM (Kingsley Morse) writes: >DS> I am not aware of any evidence for genetic type algorithms actually >DS> playing a role in biological learning. > >My understanding is that twin studies have shown that intelligence is >inherited. (Twin studies measure twins who were separated at birth, to >distinguish between inherited and environmental effects.) I'm assuming that >if intelligence is inherited, then it's encoded in chromosomes, and thus >operated on by GAs. I think that the issue of the inheritance of human intelligence is more complicated than that. First of all, in studying this question, one must separate actual inheritance from environmental effects. Twins separated at birth are close to ideal; although they might both have been influenced by having been in the same womb together. Taking an egg cell, letting it divide a number of times, splitting up the result, and implanting all these cells in several different women who all live in different cultural environments would be ideal. Stephen Jay Gould in _The Mismeasure of Man_ and Richard(?) Lewontin and Stephen(?) Kamin in _Not In Our Genes_ all give a severely critical look at the question of the inheritance of intelligence, and find the evidence somewhat lacking. Consider the fate of one of the leading advocates -- Sir Cyril Burt, who had published his results in a journal that he had edited. There were several twin studies whose correlation coefficient had remained unchanged -- despite a change in the (alleged) sample size. Two women who had supposedly worked on some of these papers were nowhere to be found. When these issues were raised in the late 1970's, Kamin(?) and others concluded that Burt had faked some of his data. His defenders, like Richard Herrnstein, denied the charge of fakery, but attributed Burt's "results" to carelessness. But on a more fundamental level, the potential for being able to do what we do is certainly inherited. What the twin studies would reveal would be any genetic component in _variation_ between individuals. If all people had the same "inborn" intelligence, then genetic studies would not reveal any difference between one individual and another. And there may well be several kinds of "intelligence." For example, understanding language and generating language appear to be two separate activities; tests on people with brain damage sometimes reveals that only one of these capabilities is present. I think this result (if it holds up) is very importaint for Artificial Intelligence work -- it would imply that doing one thing well may not translate easily into doing another thing well. Thus, a system that is good at vision may not be good at language comprehension or coordination of a robot arm. Loren Petrich, the Master Blaster: loren@sunlight.llnl.gov Since this nodename is not widely known, you may have to try: loren%sunlight.llnl.gov@star.stanford.edu