© 1975-1979, 2008 Robert A. Freitas Jr. All Rights Reserved.

Robert A. Freitas Jr., Xenology: An Introduction to the Scientific Study of Extraterrestrial Life, Intelligence, and Civilization, First Edition, Xenology Research Institute, Sacramento, CA, 1979; http://www.xenology.info/Xeno.htm

Chapter 14.  Extraterrestrial Intelligence

"In the fossil record contained within the rocks of the Earth we have watched the succession over billions of years of one more-capable creature after another, each trying some new device to aid survival, be it camouflage, many legs, large size as in the dinosaurs, and so forth. Of all the things that have been tried by the creatures of Earth, only one characteristic has continuously been retained and improved throughout the entire succession of species -- intelligence."
          -- Frank D. Drake (1967)⁵⁴

"There does not seem to be any evidence for evolutionary selection against intelligence once it has begun to appear."
          -- J. P. T. Pearman (1963)¹⁰⁵⁵

"Knowledge that other beings had safely passed their nuclear crises would give us renewed hope for our own future. It would help to dispel present nagging doubts about the survival value of intelligence. We have, as yet, no definite proof that too much brain, like too much armor, is not one of those unfortunate evolutionary accidents that leads to the annihilation of its possessors.
          -- Arthur C. Clarke (1973)⁸¹

"They’ll be extinct soon -- and -- and they don’t even care." She shuddered. "All they do, all they can do, is sit before their caves and think. Probably they think godlike thoughts, but they can’t summon even a mouse-like will. That’s what a vegetable intelligence is; that’s what it has to be!"
          -- Stanley G. Weinbaum, "The Lotus Eaters" (1935)¹⁵⁶¹

"The price of awareness is eternal uncertainty."
          -- Janet O. Jeppson, The Second Experiment (1974)²¹⁶⁴

"There’s a story about a psychologist who was studying the intelligence of chimpanzee. He led the chimp into a room full of toys, went out, closed the door and put his eye to the keyhole to see what the chimp was doing. He found himself gazing into a glittering interested brown eye only inches from his own. The chimp was looking through the keyhole to see what the psychologist was doing."
          -- from "Keyhole" by Murray Leinster (1951)³²⁰⁶

In Chapter 3 we suggested that there are basically two distinct ways of viewing the question of intelligence. First, there are the "structural" approaches which attempt to define intellect in terms of specific physical characteristics of neural equipment -- brain mass, neurological complexity, and so forth. These were briefly discussed in that earlier chapter, and were found to be somewhat useful in comparing relative intelligence levels among the fauna of a single world (Earth).

But structural definitions are suspect in xenobiology because they tend to restrict the universe of discourse. While we hope that we have at least a vague notion of what intelligence does or ought to do, there may be many physiological -- structural -- ways of building a biological unit to do the same job. For this reason, probably the majority of xenobiologists would favor a functional definition of intelligence over a merely structural one. This would appear to be the only way to avoid the peculiarities and limitations of the mental organs found on Earth.

What is the best way to set forth a functional definition of sentience? Some writers have advocated a "checklist" approach. The suspect creature should be carefully observed, they urge, and watched for signs of a specific constellation of behaviors from which smartness can be inferred. Typical list items include: Faculty of reason; ability to fashion and use tools; proficiency with language; predisposition to learn from experience, or "mental plasticity"; forethought and equilibration; creativity, insight, and intuition; ability to transmit culture; sociability; use of logic; ability to symbol; curiosity; ability to perceive spatial, temporal, numerical, or abstract relationships; imagery and the ability to construct perceptual worlds; memory; and self-awareness or consciousness.

Such definitions, while perhaps adequately circumscribing the bounds of human intelligence (and this is questionable), actually tell us little about the nature of intellect as a general force in nature. Checklists tend to be anthropomorphic, culture-limited and starkly geocentric, and as such afford no real insight into the possible character of alien intelligence elsewhere in the Galaxy.

A somewhat more generalized intellect-defining behavioral hierarchy has been suggested by the well-known Harvard University entomologist Dr. Edward O. Wilson. He divides evolved intelligences into three distinct levels:

1. Lowest grade -- the complete instinct-reflex machine. Representative organisms (sponges, coelenterates, flatworms on Earth) are so simply constructed that they must depend largely or wholly on token stimuli from the environment to guide them.

2. Middle grade -- the directed learner. These organisms (arthropods, cephalopods, cold-blooded vertebrates and birds) have a fully elaborated nervous system with some programming, some learning. Typically it is narrow in scope and limited in responsiveness to a narrow range of stimuli. It results in behavior as stereotyped as the most neurally programmed "instincts."

3. Highest grade -- the generalized learner. These organisms (humans, primates, social canids) carry a wide variety of memories, some of which have only a very low probability of ever proving useful. Insight learning may be performed, yielding the capacity to generalize from one pattern to another and to juxtapose patterns in ways that are adaptively useful. Few if any complex behaviors are wholly preprogrammed morphogenetically at the neural level. Perception of history, in the broadest sense, is a key feature.⁵⁶⁵

Wilson’s system provides an evolutionary progression, a standard against which extraterrestrials might theoretically be measured. Yet this definition -- rather, identification -- of intelligence suffers from many of the same weaknesses of the checklist approach. The fundamentals of thinking simply are not addressed.

Roger A. MacGowan, an aerospace computer scientist formerly at the Redstone Arsenal in Alabama, recognized that the key to understanding alien intelligence lies in data processing.⁷²⁹ The thinking process, he notes, consists of an arbitrary number of information-processing functions which may be carried out by living creatures. MacGowan selected five criteria which he believed to be both necessary and sufficient to specify intellectual functioning in any life-form in the universe:

1. Input -- An organism must be capable of reacting to physical events occurring in its environment. If it has no sensory input, it has no information to process and thus cannot think.

2. Storage -- Without the ability to remember, a creature could not learn. All data processing would have to proceed in real time, with full throughput and no delays. Such a being would perceive no past or future, merely an ever-present now. Since the primary function of life is to accumulate information and structure, it is hard to see how a creature without memory could possess an adaptive and useful intellect without recollection of the past.

3. Deduction -- The ability to compare current input information patterns with stored information patterns is a crucial intellective function. By making such an association, the creature becomes able to respond to the present on the basis of its past. The ability to use the generalizations formulated yesterday to respond to the problems of today is of great selective value in the struggle for survival.

4. Induction -- Inductive thinking must be considered a prerequisite for thinking, because it provides "a means of altering stored information patterns as a function of each input information pattern in such a way as to form or modify generalizations on the basis of experience." With induction, an organism is able to respond to its future on the basis of its past.

5. Output -- After it has decided what to do, an intelligent being must act. This output may manifest itself either as physical or mental activity.

MacGowan’s criteria for intelligence, if we accept them at face value, are probably sufficient for the purposes of the First Contact Team. Yet they provide more identification than explanation of what intelligence does. Our search is not quite ended, but we sense that we are on the right track.

It is interesting to note that the processes of intelligence are remarkably similar to those of life itself. The methods used by brains to collect and order environmental information recapitulate the methods used by natural evolution. To perform the functions suggested by MacGowan, for instance, brains or nervous systems must collect data, filter and reject irrelevancies, store and process that which is relevant, and then arrive at some conclusion based on the input stimuli. The techniques of natural selection are quite similar. Thousands, millions, or even billions of organisms -- the "data bits" of evolution -- are "fed" into the environment. There they are shuffled, ordered, discarded and selected according to fitness -- that is, they are "processed" through the environment. The species as a whole picks up information thereby and collectively "learns" how to survive, storing the hard-won data in the community gene pool.

It is easy to view intelligence, on the one hand, as a kind of speeded-up evolution of sensory data, or to view natural evolution, on the other hand, as a "painstaking and slow, but implacable, intelligence."¹⁰⁰⁰

Life is a negentropic process that extracts order from the environment and stores it in a complex structure. How much alive is determined by how complex the structure is. Life is properly defined along a spectrum -- the greater the data, the more alive the lifeform. Similarly, intelligence is a negentropic process by which information is extracted from the sensory data stream generated by stimuli in the environment. Again, we claim, the greater the data flow the smarter the lifeform. Intelligence, like life, cannot be defined in a yes/no manner but must be viewed in terms of a spectrum of functionality.

Even primitive protozoans have rudimentary neural apparatuses, and can be trained to do simple tasks such as swim up glass capillary tubes and cling to sterile platinum wires. More advanced creatures such as earthworms and snails are easily trained to perform more complicated "tricks." We find the glimmerings of higher intelligence in the most modest of Earth’s inhabitants, a striking example of evolutionary convergence on a grand scale which should provide some clue as to its ubiquity on other worlds.

Intelligence, indeed, seems as inevitable as life itself.³²⁴¹

Last updated on 6 December 2008