SETI: A Critical History
Part II Expanding the ETI discourse
Chapter 4. The rehabilitation of "mind"
We were not out to reform behaviorism, but to
– J. Bruner
In this chapter we briefly explore a major development in the field of psychology
that had important consequences for the ETI discourse and thus, ultimately,
the SETI project. SETI's architects came of age intellectually at a time
when behaviorist psychologists considered the concept of "mind" to be embarrassingly
unscientific. As such, the SETI scientists probably spent little –
if any – time thinking about the possible "nature" of ETI as they
designed their project. Instead, they made the default assumption of the
traditional ETI discourse: that an ETI had a humanoid cognitive structure,
consciousness, and intelligence.
Ironically, at about the same time SETI got underway experimental psychologists
began to embrace assumptions and methods that brought about major changes
in their field. The vocabulary of cognitive science, as the emerging field
came to be known, enabled scientists to discuss human cognition, consciousness,
and intelligence with a new legitimacy. This, in turn, profoundly changed
the ETI discourse. For the first time the discourse became self-consciously
aware of its traditional assumption of humanoid ETIs. Moreover, contributors
to the discourse used the new tools of cognitive science to imagine non-humanoid
ETIs. The ETI discourse expanded dramatically as the new question about
the possible nature of ETI joined the traditional question of whether ETIs
exist. As the discourse expanded, SETI became grew increasingly disconnected
from it. For the first time critics noted SETI's traditional assumption
of humanoid ETIs and to imagine the difficulties SETI might have understanding,
or even detecting, messages from the new, non-humanoid ETIs.
At the beginning of the 20th century many psychologists felt their field
did not enjoy the same institutional status given to "hard" sciences. They
believed this to be the result of psychology's methodology – it relied
heavily on the subjective technique of introspection – and the fact
that psychological theories included non-empirical constructs such as mind
and consciousness. By 1913 John B. Watson thought he and his colleagues
had restructured the field in a way that addressed these issues. In his
essay "Psychology as the Behaviorist Views It" Watson proclaimed the field's
new mission to be the prediction and control of behavior.82 Behaviorism
studied stimuli and the responses elicited by those stimuli; behavioral
psychologists ignored what went on inside the mind. Behaviorists now claimed
their empirical foundation to be as "hard" as that of any science. According
to Thomas Leahy, a historian of psychology, "by 1930, behaviorism was well
established as the dominant viewpoint in experimental psychology."83
During the 1930s, when the oldest of SETI's architects commenced their undergraduate
studies, B. F. Skinner's "radical behaviorism" began to gain favor among
psychologists. It was radical because it not only chose to ignore the role
an individual played in intermediating stimuli and responses, but went so
far as to say that an individual had no role: one's environment
determined how individuals behave.84
SETI's architects and the behaviorists were kindred spirits, in that both
sought to establish a field of inquiry on rigorously scientific grounds
and thereby gain more respectability among scientists. Ironically, by the
time the SETI project crystallized psychology had already entered yet another
period of dramatic transformation. Over a twenty-year period just prior
to Drake's first search, a number of brilliant insights each exerted an
enormous influence in its field. Together, these insights enabled psychologists
to discuss concepts like cognition, consciousness, and intelligence with
a previously unattainable degree of scientific rigor. The concept of mind
was rehabilitated from the dustbin to which the behaviorists had proudly
dispatched it. The dominant paradigm in experimental psychology shifted
from behaviorism to what we today call cognitive science, in which behaviorism
plays a relatively minor role. An early cognitive scientist, Jerome Bruner,
recalled "what I and my friends thought the revolution was about back there
in the late 1950s.... We were not out to 'reform' behaviorism, but to replace
This is not the place to attempt even a brief history of these important
changes. But I do want to identify some of the milestones in this transformation
because the insights that underwrote this change also made possible the
new thinking about the nature of ETI that transformed the ETI discourse.
Once scientists identified a vocabulary that could describe a being's nature
in ways the scientific community considered legitimate, they used it to
articulate ideas about how ETI's nature might differ from that of humans.
The timing of these transformational events is particularly relevant. The
conceptual ground was shifting under the SETI pioneers' feet even as they
designed their project. The Soviets enjoyed the benefit of just a few additional
years before they commenced CETI, and the extra time afforded them better
access to the new tools of cognitive science.86
One obvious starting point of this transformation was the claim by Alan
Turing in 1936 that a machine that could perform logical calculations, a
property previously attributed exclusively to the human mind.87
Then, in a 1943 article, the neurophysiologist Warren McCulloch and the
logician Walter Pitts formalized the analogy between a computer and the
human mind. They "showed that the operations of a nerve cell and its connections
with other nerve cells (a so-called neural network) could be modeled in
terms of logic. Nerves could be thought of as logical statements, and the
all-or-none property of nerves firing (or not firing) could be compared
to the operation of the propositional calculus, where a statement is either
true or false."88 John von Neumann's description around the same
time of stored computer programs provided the last important idea needed
to complete the metaphorical link between the human mind and a computer.89
Also in 1943, Norbert Weiner and two colleagues published the first paper
on cybernetics. The core of cybernetics was a very specific kind of information
called feedback. A simple example is a thermostat. Information about the
actual temperature is compared, in a feedback loop, to the desired
temperature, and some kind of purposive behavior results. If, say, a room
is colder than the desired temperature, that information causes the heater
to turn on; when the room reaches the desired temperature, information about
that state causes the heater to turn off. In a sense, the heater "learns"
when to turn itself on and off. The feedback loops of cybernetics that produced
purposive behavior represented another way to explain the working of the
human mind in terms of a concrete machine process rather than the abstract
introspective and philosophical notions of mind that the behaviorists wanted
to discard. Cyberneticists saw machines and humans – and many other
entities, like economies, societies, and ecosystems – as self-regulated
Once computers, the computer metaphor of mind, and self-regulating systems
that could learn appeared, the idea of artificial intelligence soon followed.
In 1950 Turing published a paper, "Computing Machinery and Intelligence,"
that is widely credited with defining the field of artificial intelligence
by specifying what behaviors a machine would have to exhibit in order to
be considered intelligent. Cognitive scientists turned this insight around,
using Turing's paper to support their use of the computer as a metaphor
for the brain.91
Claude Shannon's formulation of "information theory" was arguably the most
critical step in the transformation. Like many of the pioneers of cognitive
science Shannon formulated his ideas while working on military projects
during World War II. It is hard to overestimate the impact Shannon had;
the Digital Age would not have happened until someone had Shannon's insight
that information could be reduced to binary digits (bits).92
The significance of information theory for cognitive science lies in the
fact that information can be treated like a physical quantity – it
can be measured and modeled – without having to also explain its semantic
content. Information can be experimentally studied in a way that concepts
like consciousness could not.
In 1956, the year of the Dartmouth conference on artificial intelligence,
George Miller published an early paper on the phenomenon now referred to
as chunking.93 The AI pioneer Marvin Minsky once calculated
that a being looking at a scene containing fifty objects would be able to
assemble them into a quadrillion different sets.94 Because
such a vast amount of information from both its external and internal environments
bombards any sentient being, it evolves filters that attend selectively
to it. Beings also evolve processes that impose an order onto whatever information
does make it through these filters. This order is a kind of fiction that
the being constructs because doing so confers evolutionary advantage. We
normally think of these narratives constructed by a being about its environment
and its self as external and internal realities. The significance,
insofar as SETI is concerned, lies in the fact that different beings chunk
the available information differently, because they have had different evolutionary
histories. In other words, different beings construct realities differently.
The year before Cocconi and Morrison published their paper, the AI pioneers
Allen Newell and Herbert Simon published a paper arguing that a psychological
theory, in an obvious departure from behaviorism, "should explain ... what
processes are used and what mechanisms perform these processes." Also, in
their theory "an explanation of an observed behavior of the organism is
provided by a program of primitive information process that generates this
behavior." Mind was once again an object of legitimate study, and the computer's
ability to process information served as the preferred model for it.95
Finally, in 1959, the year of Cocconi's and Morrison's paper, Noam Chomsky
set the field of linguistics on a new path. In a review of Skinner's book
Verbal Behavior Chomsky exposed a number of weaknesses in the behaviorist
model in what the historian Leahy called "perhaps the most influential paper
in the history of psychology since Watson's manifesto for behaviorism."96
Drawing on theories he developed, Chomsky demonstrated behaviorism's inability
to explain the human use of language exclusively in terms of stimuli and
responses. Instead, Chomsky showed the necessity of internal processes
– mind – in the form of a finite number of rules than could
generate an infinite number of intelligible sentences. Chomsky abandoned
linguistics' traditional focus on meaning and substituted "information"
and "syntax." In Chomsky's linguistics the human mind performed information-processing
and symbol-manipulating functions analogous to those performed by a computer.
Language, thought by many to be the vehicle in which the mind's rationality
is embodied and made manifest, was thus the product of physical components
performing describable processes, just like a computer.97
Later Chomsky took his theory an additional step farther away from the behaviorists'
position that language was simply one more learned behavior, and an additional
step toward the rehabilitation of mind. In Language and Mind he
argued that language was a biological system. Evolution endowed us with
a universal grammar that allowed us to communicate with any healthy member
of the species. An analysis of language behavior could not yield
an understanding of language, any more than watching a bird fly could produce
an understanding of lift and the other principles of aerodynamics that explain
flight. "The major contribution of the study of language will lie in the
understanding it can provide as to the character of mental processes and
the structures they form and manipulate." Linguists, too, had joined the
ranks of cognitive scientists who studied mind from the vantage point of
The new field of cognitive science focused attention on ways that humans
constructed reality using a cognitive structure, consciousness, and intelligence
– a nature – produced by evolution. In the remainder of Part
II we examine how the ETI discourse quickly picked up these insights. The
possibility that other intelligent beings may have evolved natures that
differed significantly from ours suggested to critics of SETI that ETIs
might construct messages that SETI would find difficult or impossible to
understand or even detect.
B. Watson, "Psychology as the Behaviorist Views It," Psychological
Review 20: 158–77.
83. Thomas H. Leahy, A History of Psychology – Main Currents
in Psychological Thought, 6th ed. (Upper Saddle River, NJ: Pearson/Prentice
Hall, 2004), 377. See Chapters 11–12 for a robust history of behaviorism.
84. Morrison was born in 1915 and was working on the Manhattan
Project as a freshly-minted Ph.D. in 1945. Oliver was born in 1916,
received his Ph.D. in 1940, and then went to work for Bell Labs during
the war; he joined Hewlett Packard in 1952 as the Director of Research.
Drake and Billingham were both born in 1930. Drake entered Cornell in
1949, interrupted his studies to join the military, and got his Ph.D.
from Harvard in 1958. Billingham, an Englishman, was a physician in the
Royal Air Force from 1956 to 1963, when he joined NASA. Sagan was born
in 1934 and entered the University of Chicago in 1951.
85. Jerome Bruner, Acts of Meaning (Cambridge: Harvard University
Press, 1990), 3.
86. There are many good histories and summaries of the advances made in
cognitive science. For a concise introduction see John Tooby and Leda
Cosmides, "Forward," Simon Baron-Cohen, Mindblindness – An Essay
on Autism and Theory of Mind (Cambridge, MA: The MIT Press, 1995).
A standard textbook is Michael S. Gazzaniga, Richard B. Ivry, George R.
Mangun, Cognitive Neuroscience – The Biology of the Mind,
2nd ed. (New York: W.W. Norton, 2002). Two historical treatments are Howard
Gardner, The Mind's New Science – A History of the Cognitive
Revolution (New York: Basic Books, 1985); and Brigitte Chamak, "The
Emergence of Cognitive Science in France: A Comparison with the USA,"
Social Studies of Science 29 (October 1999): 643–84. The epistemological
issues of most relevance to the ETI discourse are discussed in Patricia
Smith Churchland, Brain-Wise – Studies in Neurophilosophy
(Cambridge: The MIT Press, 2002). A popular text is Steven Pinker, How
the Mind Works (New York: W.W. Norton, 1997).
87. Alan Turing, "On Computable Numbers, with an Application to the Entscheidungsproblem,"
Proceedings of the London Mathematical Society, Series 2, 42
88. Warren McCulloch and Walter Pitts, "A Logical Calculus of Ideas Immanent
in Nervous Activity," Bulletin of Mathematical Biophysics 5:
115-33. For a discussion of their insight see Gardner, 18.
89. John von Neumann, "First Draft of a Report on EDVAC," at www.virtualtravelog.net/entries/2003-08-TheFirstDraft.pdf,
accessed 8 August 07.
o 90. Arturo Rosenblueth, Norbert Weiner, and Julian Bigelow, "Behavior,
Purpose, and Teleology," Philosophy of Science 10 (1943): 18–24.
See Also Norbert Weiner, Cybernetics: Or the Control and Communication
in the Animal and the Machine (Cambridge: MIT Press, 1948).
91. A. M. Turing, "Computing Machinery and Intelligence," Mind
49: 433–60. For a discussion of this insight see Leahy, 420.
92. Claude E. Shannon and Warren Weaver, The Mathematical Theory of
Communication (Urbana, IL: University of Illinois Press, 1949. For
a less technical introduction to the topic see John R. Pierce, An
Introduction to Information Theory – Symbols, Signals & Noise,
2nd ed. (New York: Dover, 1980).
93. George Miller, "The Magical Number Seven, Plus or Minus Two: Some
Limits on our Capacity for Processing Information," Psychological
Review 63 (1956): 81–97.
94. Marvin Minsky, "Communication with Alien Intelligence – It May
Not Be as Difficult as You Would Think," BYTE (April 1985): 134.
95. Allen Newell, Herbert Simon, and J. C. Shaw, "Elements of a theory
of problem solving," Psychological Review 65 (1958): 151.
96. Leahy, 407.
97. Noam Chomsky, Syntactic Structures (The Hague: Mouton, 1957).
98. Noam Chomsky, Language and Mind (NY: Harcourt Brace Jovanovich,
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