Where the Mind Came From

Traditional Social Science Models

The traditional "Empiricist Model", also known as the "Standard Social Science Model" (Tooby & Cosmides 1997) & the "big domain-general purpose computer model", views the contents of mind as being a social and linguistic construct.

Over the years, the technological metaphor used to describe the structure of the human mind has been consistently updated, from blank slate to switchboard to general purpose computer, but the central tenet of these Empiricist views has remained the same.  Indeed, it has become the reigning orthodoxy in mainstream anthropology, sociology, and most areas of psychology.  According to this orthodoxy, all of the specific content of the human mind originally derives from the "outside" -- from the environment and the social world -- and the evolved architecture of the mind consists solely or predominantly of a small number of general purpose mechanisms that are content-independent, and which sail under names such as "learning," "induction," "intelligence," "imitation," "rationality," "the capacity for culture," or simply "culture" (Tooby & Cosmides, 1997).

According to this view, the same mechanisms are thought to govern how one acquires a language, how one learns to recognise emotional expressions, how one thinks about incest, or how one acquires ideas and attitudes about friends and reciprocity -- everything but perception.  This is because the mechanisms that govern reasoning, learning, and memory are assumed to operate uniformly, according to unchanging principles, regardless of the content they are operating on or the larger category or domain involved.  For this reason, they are described as content-independent or domain-general.  Such mechanisms, by definition, have no pre-existing content built-in to their procedures, they are not designed to construct certain contents more readily than others, and they have no features specialised for processing particular kinds of content.  Since these hypothetical mental mechanisms have no content to impart, it follows that all the particulars of what we think and feel derive externally, from the physical and social world.  The social world organises and injects meaning into individual minds, but our universal human psychological architecture has no distinctive structure that organizes the social world or imbues it with characteristic meanings (Tooby & Cosmides, 1997). 

There are newer models that introduce a Darwinian framework e.g. the evolutionary culture theory, which explains observed variation in human cultural systems through a model of transmission with selective retention, and approaches seeking to discover cognitive universals that have evolved through natural rather than cultural selection as cognitive responses to past environments. 

Philosophical Models

The Modularity Thesis

Jerry A Fodor (1983), an influential American Professor of Philosophy, wrote in The Modularity of Mind, that the mind consists of informationally encapsulated, mandatory, fast,  neurally localised, domain-specific ‘low-level’ perceptual modules (or "faculties") with shallow outputs, feeding information to ‘higher-level’ non-modular cognitive processes. 

Fodor argued for focusing on "the structure of the mind" rather than behaviour because: "Behavior is organized, but the organization of behaviour is merely derivative; the structure of behavior stands to mental structure as an effect stands to its cause" (Fodor, 1983).  Fodor argued that only modular cognitive processes could be studied scientifically.  He was an ardent critic of connectionist models of cognitive phenomena, arguing that they cannot account for the rationality of thought.  He endorsed the strict separation of psychology from neuroscience, arguing that the neurological properties of the brain are irrelevant to its cognitive properties (Zawidzki).

Noam Chomsky, professor of linguistics, language philosopher & radical political commentator, proposed that the mind contains innate domain-specific bodies of specialised knowledge that are accessed & processed centrally by general-purpose, non-modular cognitive mechanisms (Chomsky, 1988).  This was based on his work in linguistics in which he proposed that our language skills results from our possession of an internally represented grammar of our natural language or "language organ" of "Universal Grammar" (Chomsky, 1988).  

Both Fodor & Chomsky avoided evolutionary theorising, perceiving the modules as a by-product of the expansion of the hominid neocortex.  

Many modern mind philosophers have expanded & incorporated evolutionary explanations to these modularity theories, generating a large literature in philosophy, cognitive science and linguistics.

Philosopher Richard Samuels proposes the term Chomskian modules for domain-specific systems of truth-evaluable mental representations or bodies of information that are innate & subject to  informational restrictions.  These modules are purported to be inert & non-computational, only eventuating in behaviour when manipulated by cognitive mechanisms.  He proposes that they co-exist with Darwinian modules, which evolutionary psychologists talk about (Samuels, 2000). 

Marvin Minsky, mathematician and computer scientist, proposes:

The brain's functions simply aren't based on any small set of principles. Instead, they're based on hundreds or perhaps even thousands of them.  In other words, I'm saying that each part of the brain is what engineers call a kludge — that is, a jury-rigged solution to a problem, accomplished by adding bits of machinery wherever needed, without any general, overall plan: the result is that the human mind — which is what the brain does — should be regarded as a collection of kludges.  The evidence for this is perfectly clear: If you look at the index of any large textbook of neuroscience, you'll see that a human brain has many hundreds of parts — that is, subcomputers — that do different things.  Why do our brains need so many parts?  Surely, if our minds were based on only a few basic principles, we wouldn't need so much complexity.

The answer is that our brains didn't evolve in accord with a few well-defined rules and requirements.  Instead, we evolved opportunistically, by selecting mutations that favored our survival under the conditions and constraints of many different environments, over the course of at least half a billion years of variation and selection.  What, precisely, do all those parts do?  We're only beginning to find this out.  I suspect that we have much more to learn.  When we're all done we'll have found out that many of those mental organs have evolved to correct deficiencies of old ones — that is, deficiencies that did not appear until we got so much smarter.  It's characteristic of evolution that after many new structures have developed, it's too late to go back and make much change in those older systems on which we still depend.

In a situation like that, it can be a mistake to focus too much on searching for basic principles.  More likely, the brain is not based on any such scheme but is, instead, a great jury-rigged combination of many gadgets to do different things, with additional gadgets to correct their deficiencies, and yet more accessories to intercept their various bugs and undesirable interactions — in short, a great mess of assorted mechanisms that barely manage to get the job done (Minsky M, 1995).

 

 

Evolutionary psychology

Modularism in Evolutionary Psychology

The Massive Modularity Hypothesis

The Massive Modularity Hypothesis maintains that the mind contains a large number of distinct though interconnected information processing systems that are innate domain-specific (special purpose) computational modules ("mental organs" or "mental algorithms"), shaped by natural selection (adaptations) to handle the sort of recurrent information-processing problems that confronted our hunter-gatherer ancestors (Barkow et al, 1992; Pinker, 1995; Cosmides & Tooby, 1997; Carruthers & Chamberlain, 2000; Samuels, 2000). 

“Human nature”, according to evolutionary psychologists, refers to the accumulated specialized neural circuits that are common to every member of a species and are the product of that species' evolutionary history (Cosmides & Tooby, 1997). 

Tooby and Cosmides (1995) consider these mental organs to be adaptations "invented by natural selection during the species' evolutionary history to produce adaptive ends in the species' natural environment."  "[O] ur cognitive architecture resembles a confederation of hundreds or thousands of functionally dedicated computers (often called modules) designed to solve adaptive problems endemic to our hunter-gatherer ancestors. Each of these devices has its own agenda and imposes its own exotic organization on different fragments of the world. There are specialized systems for grammar induction, for face recognition, for dead reckoning, for construing objects and for recognizing emotions from the face. There are mechanisms to detect animacy, eye direction, and cheating. There is a "theory of mind" module .... a variety of social inference modules .... and a multitude of other elegant machines. (Tooby and Cosmides, 1995)

Samuels summarises the four central tenets of evolutionary psychology as:

1. The human mind is an information-processing device that can be described in computational terms (Barklow et al, 1992). 

2. Much of the structure of the human mind is innate (in contrast to the Traditional Social Sciences Model). 

3. Our cognitive architecture is largely the product of natural selection, such that our minds are composed of adaptations that survived our species' evolutionary history because they solved adaptive problems (produced adaptive fitness with our ancestral environment or Environment of Evolutionary Adaptedness ["EEA"] coined by John Bowlby). 

4. The human mind is composed of highly specialised cognitive systems or modules, that are each dedicated to solving a restricted class of problems (Samuels, 2000). 

These "Darwinian" modules have three characteristic features:

1. Domain-specific (or "functionally dedicated") computational mechanisms, although some evolutionary psychologists do assume some degree of domain-specific knowledge within these modules (e.g. the Theory-of-Mind module). 

2. They are innate cognitive structures whose characteristic properties are largely determined by genetic factors. 

3. They are the products of natural selection (Samuels, 2000). 

The mind is thus seen as a suite of modular adaptations selected for at points in our evolutionary ancestry and maintained through inertia or continued selection.  It is a Swiss-army knife model of cognition (in contrast to large general-purpose computer), each blade representing pre-programmed algorithms that sensitise the organism to monitor specific situations and function as biases to learn certain behavioural responses rather than others.  

Murphy & Stich (1998) propose a two dimensional classification of disorders based on evolutionary psychology: network of problematic modules (x) vs. aetiology of the malfunction (y). 

Most of evolutionary psychology focuses on cognitive mechanisms rather than behaviours per se.  The evolved mechanisms are perceived to generate many beliefs and desires, but the response depends on practical reason, social adeptness and individual preferences.  

Neuroscientist Joseph LeDoux argues, with regard to the neural substrates for the emotions, that "there is no single brain system" that is "the emotion faculty" and he argues for there being a family of mental emotional modules that evolved  to solve past biological imperatives (LeDoux, 1996).

Steven Pinker, experimental psychologist, has been an extremely influential proponent of modularism, using the language module as his quintessential example:

... If language is a mental organ, where did it come from?  I believe it came from the same source as physical organs.  It's an adaptation, a product of natural selection in the evolution of the human species.  

... Language is interesting because, of course, it's distinctly human, and because we all depend on it. For centuries, language has been the centerpiece of discussions of the human mind and human nature, because it's considered the most accessible part of the human mind.  The reason people are likely to get exercised by technical disagreements over the proper syntax of relative clauses in Choctaw, say, is that everyone has an opinion on human nature, and lurking beneath such discussions of language is the belief that language is the aspect of science where human nature is going to be understood first.

If language is an instinct, what does it say about the rest of the mind?  I think the rest of the mind is a set of instincts as well.  There's no such thing as intelligence, a capacity for learning, or a general ability to imitate role models. The mind is more like a Swiss Army knife: a large set of gadgets, language being one of them, shaped by natural selection to accomplish the kinds of tasks that our ancestors faced in the Pleistocene.

Why do I call language an instinct?  Why not a manifestation of an ability to acquire culture, or to use symbols?  There are four kinds of evidence that have been gathered over the last century.

... the first two bits of evidence [are] the universality of language and the universality of the design of language — that is, the kinds of mental algorithms that underlie people's ability to talk. The third bit of evidence is from my own professional specialty, language development in children.  We see language development proceed the same way in all the world's cultures. It's remarkably rapid, as any parent can attest.  Children begin to babble in their first year of life.  First words appear at about one year of age.  First word combinations ... happen at about eighteen months.  Then around the age of two, there's a burst of about six months — even less for some children — in which one sees a flowering of virtually the entire grammar of English: relative clauses, passives, questions with "WH" words, and constructions so complex that the researchers in artificial intelligence haven't been able to duplicate them in computer systems that would allow us to converse with a computer in English. 

... And what the child has done is solve a remarkably difficult computational problem. ... This problem is way beyond the capability of any current artificial-intelligence system.  Current natural-language processing systems can't even use a single language, let alone learn to use any language.  Nonetheless that's what the child does in those six months, despite the lack of grammar lessons or even feedback from parents.  Moreover, if you crank up the microscope on baby talk, you often find that it conforms to universal constraints that characterize language across the planet. 

... Language development isn't driven by general communicative utility.  The child doesn't talk better and better just to get more cookies, or to get more TV, or to be allowed to play outside more often. 

... The final bit of evidence is that language seems to have neurological and perhaps even genetic specificity.  That is, the brain is not a meatloaf, such that the less brain you have the worse you talk and the stupider you are, but seems to be organized into subsystems.  Using brain damage and genetic deficits as tools, we can see how the brain fractionates into subcomponents.

First, there are cases in which language is impaired but intelligence is intact. For example, there are forms of aphasia, caused by strokes, in which people lose the ability to speak or understand but retain the rest of their intelligence.  A slightly less extreme condition is called "specific language impairment," or SLI [a specific learning disorder], in which children don't develop language on schedule or in a normal way: the language appears late and the children have to struggle with it.  Pronunciation improves in adulthood, with the help of lots of therapy and practice, but the victims speak slowly, hesitantly, and with many grammatical errors.  They have trouble doing certain language tasks that any five year-old can do. 

... The clincher is what people in my field call a double dissociation, where one sees the opposite kind of impairment; these are syndromes in which language is intact but the rest of intelligence suffers — a linguistic idiot savant, who can speak, and speak well, but is retarded.  There are a number of syndromes in which that can happen, including spina bifida and Williams syndrome.  In those cases, you have what therapists call chatterboxes or blatherers; a child goes on and on in beautifully formed sentences that often have no connection to reality.  This can happen in children with an IQ of 50, who cannot tie their shoes or handle money. That's evidence for the claim that language is a separate mental system, an instinct.

Why do I call language an adaptation? What is the alternative?  [Stephen Jay] Gould and [Noam]  Chomsky suggest that language is a by-product.  Perhaps, as we developed a big brain in our evolutionary history, language came automatically, the same way that when we adopted upright posture our backs took on an S-shaped curve. ... an epiphenomenon, an accident.

The argument from Chomsky and Gould is that maybe language was an unavoidable physical consequence of selection for something else, perhaps analytical processing, hemispheric specialization, or an enlarged brain. 

... What we've discovered in recent studies of language is that it, too, is an improbably complex biological system.  It's improbable in the sense that it's found only in one species, and improbable also in the sense that most of the things you do to a brain will disrupt the ability to use language. Moreover, like a watch or an eye, it has many finely meshing parts.  There is the mental dictionary, which in a typical high-school graduate contains about sixty thousand words.  There are the unconscious rules of syntax, which allow us to put words together into sentences.  There are the rules of morphology, which allow us to combine bits of words, like prefixes and suffixes and stems, into words.  There are the rules and processes of phonology, which massage sequences of words into a pronounceable sound pattern — what we informally call an accent.  There are the mechanisms of speech production, including the shape and placement of the tongue and the larynx, which seem to have been built for speech production at the expense of another biological function, like being able to breathe while you're swallowing — which other mammals can do.  There's speech perception ... And there is the ability of a child to learn all this in a very short period of time.

These facts suggest that the anatomy of language is complex, like the anatomy of the eye.  Moreover, language is quite clearly adaptive, in the sense of inherently serving the goals of reproduction.  All societies use language for patently useful things like sharing technology and inventions.  Language is a major means by which people share what they have learned about the local environment.  Also, social relations in the human species are largely mediated by language.  We rise to power, manipulate people, find mates, keep mates, win friends and influence people by language.  Moreover we, and every human society, value people who are articulate and persuasive, which certainly sets up pressures for better language.

Those two lines of evidence suggest that language meets the criteria for an adaptation and a product of natural selection. 

... If language is innate, then how much else is?  Is carburetor repair innate?  Is innateness a slippery slope?  Of course not! The idea of a general-purpose learning device in an otherwise blank mind is so deeply entrenched that for many people it is inconceivable that there could be anything other than the two extremes: at one end, nothing is innate; on the other end, even the ability to repair carburetors is innate.

But research in psychology, linguistics, and AI have shown that there can be an interesting intermediate position.  All the wonderful complex things that people do — repairing carburetors, following soap-opera plots, finding cures for diseases — might come out of the interactions among a smaller number of basic modules.  The mind might have, among other things, the following: a system for intuitive mechanics — that is, our understanding of how physical objects behave, how things fall, and so forth; an intuitive biology — that is, expectations about how plants and animals work; a sense of number, the basis of mathematics and arithmetic; mental maps, the knowledge of large territories; a habitat-selection module, recognizing the kinds of environments we feel comfortable in; a sense of danger, including the emotion of fear and a set of phobias all humans have, like fear of heights and of venomous and predatory animals; intuitions about food, about contamination, about disease and spoilage and what is icky and disgusting.  Monitoring of current well being: is my life going right? Is it all O.K., or should I change something?  An intuitive psychology — that is, an ability to predict people's behavior from knowledge about their beliefs and desires (which, incidentally, seems to be the module that is defective in autism).  A mental Rolodex, in which we store knowledge of other people and their talents and abilities.  The self concept: our knowledge of ourselves and how to package our identity for others.  A sense of justice, rights, obligations.  A sense of kinship, including the tendency towards nepotism.  A system concerned with mating, including sexual attraction, love, and feelings of fidelity and desertion (Pinker, 1995).

Sociobiology & Behavioural Ecology

This intellectual movement discovered that the struggle is not among species but, ultimately, among genes (Hamilton 1964; Williams 1966; Wilson 1975; Dawkins 1976).

The adaptive function of behaviour is emphasised (Alexander, 1974; Wilson, 1975, 1978).  Behavioural variability is viewed as demonstrating that organisms possess a flexible repertoire of optimised responses to different environmental conditions.

Areas where sociobiology is influencing the understanding of psychopathology:

For more information:

Ethological (Animal) Models

Charles Darwin (1872/1965) and other ethologists have demonstrated that it is the communicative aspect of emotions that is the most significant for survival.  Darwin collected extensive evidence that emotional signaling among animals is primarily coded in the activity of the muscles of the face in The Expression of the Emotions in Man and Animals.  Darwin established that many of the fundamental emotions human beings communicate by changes in facial expression are similar to those employed by other social animals, particularly the primates, and other mammals who care intimately for their young.  Darwin determined from his research that human emotions were remarkably uniform across cultures and similar to the communication of other social mammals.  He emphasised that the emotions are a preverbal system of social signaling in constant use in addition to language.  He said that the recognition & expression of primary emotions of pleasure, grief & fear is fundamental behaviour of the brain as universal as the ability to identify the primary colours.  

Ivor Jones & Judith K Blackshaw (2000) propose a new aetiological approach to psychiatry based on evolutionary theory using ethological principles.  They  propose that much psychiatric behaviour can be understood by using two categories: (i) normal evolved adaptive behaviour, which has become excessively prominent and (ii) a distortion of adaptive behaviours by some pathological process.

Regarding personality disorders:

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Citation suggestion: Dr Gary Galambos, Social Science ModelsEvolutionary Psychiatry Interest Group Sydney Australia (http://www.ep.org.au/models/socsc.htm) [date accessed]

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