onegoodmove

A basic tenet of evolutionary psychology is that “cognition is sub served by a number of innately channeled, domain-specific systems…” (Carruthers & Chamberlain 2000, p. 1) One example is an innate cheater detection module (Cosmides 1989). One reason ‘innateness’ has been so unclear is the multi-disciplinary nature of cognitive science. Behavioral geneticists, developmental psychologists, and philosophers each bring there own understanding of what innateness is to the debate. This results in a lot of confusions and cross-talk result. The concept is important because the experiments performed, the information deemed relevant from observation, and the way results are interpreted all depend in part on what notion of innateness is being employed. The purpose of this paper is to get clear about what is required for a good account of innateness.
I will begin by making some distinctions. First, I will discuss what it is that cognitive scientists are trying to explain by invoking innateness and what a good explanation would look like. I will do this by making use of two stories in Fiona Cowie’s (Cowie 1999) excellent book, “What’s Within: Nativism Reconsidered.” Cowie’s stories will help me make a cautionary distinction between what’s innate and what innateness is. They will also point the way to a distinction between adaptive evolutionary explanation and developmental explanation. Next, given this distinction, I will argue that most innateness claims are developmental claims and should be given developmental explanations. I will show that three current accounts of innateness blur this distinction in a way that is damaging to research in cognitive science. I will also point out some other shortcomings of these accounts. Finally, I will suggest what is needed for a useful and clear developmental account of innateness.

2. What’s Innate and What Innateness Is

What question is innateness invoked to answer? Fiona Cowie suggests it might be trying to answer the genetic question also known as Plato’s problem. Where does what is in our minds come from? Cowie gives us good reason to reject the other traditional use of innateness, namely as a foundation for a rationalist epistemology. I will not go into epistemology here and take it that she is correct about this. We have good reason to think that the innateness controversy is about the genetic question. Noam Chomsky, perhaps the most important example of a nativist, sees innateness as an answer to this question. “For many years, I have been intrigued by two problems concerning human knowledge. The first is the problem of explaining how we can know so much given that we have such limited evidence. The second is the problem of explaining how we can know so little, given that we have so much evidence. The first problem we might call ‘Plato’s problem,’ the second, ‘Orwell’s problem’ …” (Chomsky, 1986 p. xxv) However, Cowie argues that there is no substantive debate between nativists and empiricists on the genetic question. She argues that the substantive debate lies elsewhere. Cowie’s discussion illuminates some important distinctions about innateness explanations and shows us the kind of explanation we want. However, Cowie is incorrect in part about where the substantive debate might lie.
Cowie begins with Peter Godfrey-Smith’s distinction between internalist and externalist explanations. An internalist explanation for Godfrey-Smith explains “one set of organic properties in terms of other internal or intrinsic properties of the organic system.” (Godfrey-Smith 1996, p. 30) Externalist explanations explain “properties of organic systems in terms of properties of their environments.” (Godfrey-Smith, 1996, p. 30) So, under this schema empiricists are externalists and nativists are internalists. As Cowie points out, it is clearly the case that this won’t do. Nativists and empiricists allow for some explanations of both sorts. Ned Block point out that, “No organism can learn without a mechanism that accomplishes this learning. Hence at least one learning mechanism must be innate (if only a mechanism for acquiring other learning mechanisms).” (Block 1981, p. 279) Godfrey-Smith is aware of this and softens his distinction. He argues that internalists place greater weight on internalist explanations and externalists place greater weight on externalists explanations. Thus we have more of a continuum of explanations rather than a hard and fast distinction. Nativists and empiricists disagree about which factors, internal or external, play a greater role in the genesis of what is in our mind/brain.
Cowie argues that given this distinction, it can often be the case that the innateness debate is insubstantial. Cowie does this by an ingenious little story. She asks us to consider two possible explanations of how normal facial features develop in a human fetus. Gus the geneticist says genetic factors are most important in determining whether, say, our eyes are in the front of our head. Harry the epidemiologist says environmental factors are more important. For example, alcohol in the maternal blood stream can cause eyes to be elongated toward the side of the baby’s face. The problem is that Gus and Harry are giving explanations for slightly different questions. “The ‘internalist’ Gus, is explaining why a fetus normally comes to have eyes on the front (rather than the sides or top or back, say) of its head. The ‘externalist,’ Harry, is explaining how a fetus comes to have normal-sized eyes close to the center of its face rather than the larger, elongated eyes toward the side of its face that are characteristic of fetal alcohol syndrome.”(Cowie 1999, p. 22) Each explanation has a different contrast. Both are good explanations, but they reflect different explanatory interests. They simply aren’t in conflict.
Cowie argues that you can have a substantive debate if the explanatory contrast is the same for both sides. Chloe the molecular biologist and Minnie the epidemiologist are both interested in “why the facial features characteristic of fetal alcohol syndrome (rather than normal features) develop in a certain class of cases.” (Cowie 1999, p.23) Chloe says the defective FAS1 gene provides the most important explanation while Minnie attributes it to alcohol consumption during pregnancy. While it may be obvious that both these causes are relevant, it is not obvious which might be the major contributor and thus the most causally relevant. Cowie’s diagnosis of why Chloe and Minnie have a substantive debate and why Gus and Harry don’t is very enlightening. Chloe and Minnie are asking the same question whereas Gus and Harry are not. Chloe and Minnie’s question makes the same contrast. Second, Chloe and Minnie are not talking about fetal development in general, rather they have something very specific they are investigating. This is the lesson to be learned from Cowie’s two stories. “These contrasts suggest that disputes between internalist and externalists are substantive when they concern the particular ways that particular causal elements contribute to particular causal processes.” (Cowie 1999, p. 24)
Cowie argues that nativists and empiricists don’t seem to be arguing about particular contrasts and that this is a good reason to reject the internalist/externalist picture of innateness. She expects this picture will result in the Gus and Harry story where scientists are just talking past one another. The problem seems to be that although it may be possible to have substantive debates at the level of particular problems as in the Chloe and Minnie case, there does not seem to be a common contrast that nativists and empiricists make in general.
For example, an argument made in favor of nativism that is at a more general level is the poverty of stimulus argument. Cowie points out that the poverty of stimulus arguments is a negative a argument. We can see this in Chomsky's discussion of the matter, “The Language each person acquires is a rich and complex construction hopelessly underdetermined by the fragmentary evidence available. Nevertheless individuals in a speech community have developed essentially the same language. This fact can be explained only on the assumption that these individuals employ highly restrictive principles that guide the construction of grammar.” (Pinker 1994, p.23)# Poverty of stimulus arguments are arguments that try to show that empiricism cannot be correct. One cannot the positive thesis that a trait such as language is innate. On the internalist/externalist picture arguing not empiricism doesn’t provide a specific contrast like the contrast in the Chloe and Minnie story.
What is Cowie’s alternative? She argues that the substantive debate between nativists and empiricists is the following. “Whereas empiricists stress the generality of our innate learning mechanisms, nativists use arguments from the poverty of stimulus to defend their view that since certain learning tasks require special kinds of skill, the mind must contain special purpose, or task-specific learning mechanisms in addition to those that empiricists allow.” (Cowie 1999, p.30) Cowie is trying to show us what is at issue between nativists and empiricists without ever telling us what innateness is. What she has done here is dodge the question. She simply does not give a new account of innateness. Whether a trait is domain-specific is orthogonal to an account of innateness. It may well be that one could have domain specific capacities that are learned. It is possible that we have one innate learning mechanism that allows us to acquire other domain-specific learning mechanisms. The nativist invokes the poverty of stimulus argument to show that there is a domain-specific learning mechanism that is also innate. Cowie seems to think that innateness is just being inborn! “Nativism, seen from this perspective is the view that our inborn intellectual skills are domain-specific.” (Cowie 1999, p. 30). It is important to distinguish between what is innate and how it is innate, on the one hand, and what innateness is on the other. We cannot be clear on what the issue between nativists and empiricists is without having a better conception of innateness than “inborn.”

3. Explanatory Strategies

Suppose I am telling somebody about language. This person, I will call him Ivan, says, “Oh, you are studying language acquisition, how do children learn language so quickly and easily?” I answer him by saying “It’s human nature to learn language quickly and easily.” How would we expect him to respond? He might say, “don’t patronize me, this much is obvious, I wanted to know how they do it, tell me the steps they take along the way to learning the language.” It’s not that what I said was false that was the problem for Ivan. The problem was that I was not answering the question Ivan was asking. How can we make the distinction between Ivan’s question and the question I answered. I suggest in the same way Cowie made a distinction between Gus and Harry on the one hand, and Chloe and Minnie on the other hand. We ask what contrast each is making. I wish to distinguish, as Ariew does (Ariew 1999), between two explanatory strategies. They are adaptive evolutionary explanation and developmental explanation. At first blush, the answer I gave to Ivan is an adaptive evolutionary explanation while the question he was asking was a developmental question. Below I will compare and contrast these two types of explanation and follow by illustrating how these strategies relate to innateness by way of an example.
I start with adaptive evolutionary explanation. An adaptation is a trait that was selected for because it contributes to the survivability of a species in a given habitat. For example, a Giraffe’s long neck allows it to get at a food source high up on a tree. The Giraffe’s neck contributes to its survivability in a habitat with tall trees. This trait is considered adaptive by way of Darwin’s theory of natural selection. Adaptive explanation works at the level of population. It explains the relationship between a trait and the habitat it is adapted too. This relationship can be captured statistically by using the behavioral geneticist notion of heritability. Heritability in a population is described in the following way. “The distribution of the trait in an offspring population is predictable from the distribution of the trait in the parent population and the mating pattern of that population.” (Horvath 2000). Thus heritability can be characterized by the following contrast. The variation between individuals within a population arises from differences in the genome rather than differences in the environment those individuals inhabit.
Developmental explanations work at the level of a the individual. A developmental explanation gives us a causal history from the genotype to the phenotype. Alternatively, developmental explanation gives us a causal history from an initial state of not having some trait, knowledge, or capacity to having it. In other words developmental explanations give us the mechanism in an individual that produces a particular outcome.
Adaptive evolutionary explanation black boxes these mechanisms. The reason for this is that natural selection does not care, as it were, how you get to an adaptive outcome just so long as you get the right outcome. Developmental explanations are not concerned with population level variation of outcomes. Another difference is that adaptive evolutionary explanations count what constitutes an ‘environment’ differently than do developmental explanations. Whereas the chemical environment that DNA finds itself in is sometimes treated as the environment in developmental explanations, adaptive evolutionary explanations hold this type of ‘environment’ constant. The following example will make these distinctions clearer.
Andy Clark uses this example for very similar purposes. (Clark 1998) Phenylketonuria, known as PKU disease, is a horrible disease that causes mental retardation, shortness of stature and lack of pigment. The normal gene at the PKU locus produces a liver enzyme that allows us to metabolize phenylalanine, an amino acid that is common in lots of foods we commonly eat. People with PKU disease cannot produce this important enzyme, phenylalanine hydroxylase. The phenylalanine concentration in the blood gets too high and this interferes with the production of myelin, which serves as a protective sheaf around our nerve cells. Without this sheaf, the deleterious effects mentioned above occur. Fortunately, these effects are easily avoided. A person with this disease simply has to avoid phenylalanine in their diet. If we give an adaptive evolutionary explanation of this disease it will be considered heritable. The contrast question that an evolutionist might use is why did Mary have the deleterious effects rather than other people from her town. Since everybody in her town eats roughly the same things, this is not the difference that makes a difference in Mary’s having the deleterious effects of PKU. What is different about Mary is that she is homozygous at the PKU locus. For this reason, adaptive explanation attributes the cause of her disease to the PKU gene.
What would a developmental explanation for this disease look like? The developmentalist is not making a population level contrast. She is asking something like, why and how do these deleterious effects occur in Mary rather than Mary living a healthy normal life. Whereas the an adaptive explanation can take the chemical environment of the gene and the chemicals such as phenylalanine coming in from outside the organism as a backdrop, these things are all causally relevant to the developmentalist. While it may be obvious that both the gene and phenylalanine are causally relevant, it is not obvious which might be the major contributor and thus the most causally relevant. Suppose we ask how the PKU gene produces PKU symptoms. We see that adaptive evolutionary explanation works at a population level while developmental explanation is at the level of the individual. Given the contrasts that come out of explanations at these two levels, the evolutionist can take much of the environment as back drop, thus what counts as environment is much narrower. The developmentalist must have a broader conception of environment. Finally, adaptive evolutionary explanation is interested in outcomes and developmental explanation is interested in the mechanisms that produce those outcomes.
Cowie’s suggestion that innateness is a concept used in answering the genetic question or the ontogeny of our cognitive structures is correct. Here I take a very brief look at a famous innateness claim in the literature and show how it is a developmental claim. Noam Chomsky claims that our knowledge of universal grammar is innate. Chomsky argues that a number of observations lead us to this conclusion. We are capable of producing an infinite variety of sentences, but our lifetime is comparably quite short. The information we get while learning language is very limited. Differences in intelligence don’t seem to effect language acquisition one way or the other. “Such observations lead one from the start, that we are dealing with a species-specific capacity with a largely innate component.” (Chomsky 1975, p.123) Chomsky speaks of a species-specific capacity. This is an observation at the level of population and certainly not at the level of the individual. This seems very much like an evolutionary explanation and indeed Chomsky makes evolutionary claims about language as well as developmental ones. Chomsky may be making these observations as a defensible guide to a developmental conception of innateness. It is important; however, to keep the distinction between explanatory strategies in mind when these observations are made. Here we see Chomsky making a developmental claim. “The competence of an adult, or even a young child is such that we must attribute to him a knowledge of language that extends far beyond anything he has learned.” (Chomsky 1975, p. 123) Chomsky is saying something about how people come by or acquire their linguistic competence. Linguistic competence is the outcome of a developmental process and Chomsky claims that this outcome requires more knowledge than we could learn in the normal course of development. “The central problem in designing a language acquisition device is to show how such a system of rules can emerge given the data to which the child is exposed.” (Chomsky 1975, p. 124) Again we see Chomsky making claims about how an outcome “emerges.” What seems confusing in Chomsky’s work and that of others in cognitive science is they do not make it clear whether their arguments that invoke talk about the distribution of outcomes are also arguments about the development of those outcomes. What we want is a characterization of innateness that places constraints on developmental explanations of trait acquisition.

4. Current Accounts of Innateness

4.1 Andre Ariew’s Canalization Account

Andre Ariew gives potentially the best account of innateness. Ariew recognizes the different explanatory projects above and it is largely his work on this that has inspired my point of view. Despite recognizing these two explanatory strategies, Ariew believes he can somehow heroically save an account of innateness that works in either explanatory strategy. There are three related problems with Ariew’s canalization account of innateness. After summarizing his account I will show how each of these problems comes out of this distinction between explanatory strategies.
Ariew revisits the early debates over innateness between Konrad Lorenz and Lehrman. Lorenz characterized the issue as a dichotomy between traits that are genetically determined and those that are acquired or learned. Lehrman (1953) argued that no trait could develop on the basis of genes alone. Every trait requires some interaction between genes and environmental factors. Ariew diagnoses their disagreement as being caused by their different explanatory goals. Lorenz has adaptive explanation in mind and Lehrman has developmental explanation in mind. Ariew believes that Lehrman has made rather damning criticisms of Lorenz’s innateness conception but believes that there are some innocent features of it that are desirable. Ariew in effect is trying to create a middle ground view between the radical view which rejects the distinction between innate and acquired altogether and Lorenz's view that innate traits are genetically determined traits. Ariew derives three desiderata from his review of this debate.

1. “An account of innateness should make it a feature of development.” (Ariew 1999, p.14)
Ariew clearly wants his account to be relevant to a developmental explanation. So far so good, as we saw above, cognitive scientists seem to be making developmental innateness claims. .

2. “Innateness should denote an environmentally stable trait.” (Ariew 1999, p.15)
This also seems quite reasonable. As Ariew points out there are a number of deprivation experiments in ethology in which various species seem to develop traits in impoverished learning environments. Lorenz and others believe these experiments can provide evidence for innateness.

3. “An account of innateness should make clear how natural selection can effect prevalence of some adaptive traits.” (Ariew 1999, p. 15)
It is very unclear why this should be a desideratum given that innateness is supposed to be a developmental concept.

Based on these desiderata, Ariew argues that C. H. Waddington’s concept of canalization is innateness. “Canalization denotes a process whereby the endstate (the product of development) is manifested despite environmental perturbations.” (Ariew 1999, p.16) Development is considered an “epigenetic landscape” in which various developmental pathways branch off. Each of these pathways leads to a particular end state. Certain environmental features can induce an organism to follow one of these pathways. Each of these pathways can be more or less canalized. So Ariew equates innateness with canalization. “The degree to which a biological trait is innate for individuals possessing an instance of a genotype (or set of genotypes) is the degree to which the developmental pathway for individuals possessing an instance of that genotype (or set of genotypes) is environmentally canalized. The degree to which a developmental pathway is canalized is he degree to which development of a particular endstate (phenotype) is insensitive to a range of environmental conditions under which the endstate emerges.” (Ariew 1999, pp. 17-18)
It is surprising that Ariew makes the distinction between developmental explanation and adaptive evolutionary explanation and still maintains his third desideratum. Why not leave evolutionary explanation to heritability. It is only when heritability is used as an equivalent of innateness for development that it runs into explanatory problems. It need not be the case that heritability and development are unrelated. Innate traits may well be widespread in a species and their innateness would explain why this is so. However, the inverse situation is would not be the case. That is the fact that a trait is wide spread tells us nothing about the development of the trait. Developmental biologists and psychologists can give a story about a trait without the use of this notion. Meanwhile, behavioral geneticists can provide us with interesting information on the level of population. Trying to combine the two sorts of explanation leads to problems. First, Ariew ends up talking about end states or outcomes again. This is the province of evolutionary explanation. Innateness defined in terms of the outcome, again makes no useful contrast between the environmental and internal factors that combine to make something canalized. Again the developmentalist is not interested in the fact that a trait is canalized, she is interested in the precise mechanism of that canalization. It appears that though canalization pretends to be about development that it is not. Ariew thus sacrifices his first desiderata for his third.
How does canalization describe our PKU case. It seems under one construal, PKU isn’t canalized much at all. It is totally contingent upon whether the person includes phenylalanine in their diet. Thus, PKU is highly sensitive to the environment and is not highly canalized. However, PKU is very heritable. It is strange that a trait that is highly heritable is not innate. On another construal, PKU might be thought of as moderately canalized. Given the way I have characterized the disease, the genes and the environment both play relevant causal roles. Nowhere in this characterization do we get anything like my explanatory gloss of the mechanism of PKU. Canalization seems to be just another way to characterize an end state. As a resource in adaptive evolutionary explanation it may even be more useful than heritability. As Ariew points out you can tell a story about how a particular path of development may be selected for and thus parts of it may be translated into genetic instruction. As a developmental concept, canalization won’t do the job.
Another problem with canalization is that it over-generalizes. Richard Samuels makes this point in his forthcoming article. It seems that water appears in every environment that a human could be in. The concept water is acquired over a massive range of environments and thus is insensitive to a wide range of environments. Under this view, acquisition of the concept of water is highly canalized and therefore we would have to say that the concept of water is an innate concept. But clearly this is a concept we learn from experience. A concept that is learned is surely not one we want to call innate. Canalization seems fine for adaptive evolutionary explanation, but doesn’t do so well for developmental explanation.

4.2 Elliot Sober’s Invariance Account

Elliot Sober offers an account of innateness that captures some of the benefits of Ariew’s canalization account. However, it also suffers from similar failings. Ultimately Sober’s account fails because it offers nothing by way of developmental explanation.
Sober like Ariew lists a set of desiderata for innateness. They are as follows.

1. Innateness should be thought of as a continuum concept rather than a dichotomy. This is motivated by his bird song example. There are some birds that acquire their song just by listening to any bird song whatsoever. They don’t need to hear the song they end up singing. Thus the song is not acquired independently of its environment, but by some sort of interaction. It is also clear that they don’t learn the song in any traditional sense of learning. Note this case is similar in structure to the PKU case given above.

2. Innateness should not mean the trait is unmodifiable later in life. Sober points out that Egyptian Vultures initially break ostrich eggs and this trait emerges quite reliably. However, They stop this behavior if they discover that the eggs are often empty.

3. Innateness must account for the possibility of arriving at the same phenotype via an innate mechanism or via an environmental mechanism. Sober notes that in some fruit flies the number of bristles they develop is contingent upon diet, while in others diet has no effect one way or the other.
Based on these considerations Sober concludes innateness must be defined as follows. “A phenotypic trait is innate for a given genotype if and only if that phenotype will emerge in all of a range of developmental environments.” (Sober 1999)
Sober’s account is again about an outcome and not a mechanism. Knowing that trait emerges in a range of environment tells us nothing of the mechanism by which the trait emerges. Richard Samuels puts it nicely. “The fundamental flaw to which invariance accounts are subject is that they attempt to explain the central features of innateness solely in terms of a mapping relation between genotypic and phenotypic traits, without imposing any substantive constraints on the mechanisms or processes in virtue of which such mapping relations obtain.” (Samuels forthcoming, p. 12) Sober’s account doesn’t serve any useful purpose in a developmental explanation.
The key to Sober’s account seems to be how you determine the relevant “range of environments.” As Sober admits this may have to be pragmatically characterized, but then it seems that these pragmatic characterizations are doing all the explanatory work. Samuels and Ariew point out that the range of environments would have to be exceeding large indeed. Ariew writes that on the Sober account traits emerge “By means of a development mental sensitivity only to environmental factors that are themselves invariant within the organism’s developmental environment.” (Ariew 1999, p. 26) Samuels points out that such a factor is the presence of water. Are we to believe that since everybody acquires the concept water in a wide range of environments that this concept is innate? This seems highly counter-intuitive. Here we have again an account of innateness with an overgeneralization problem. Sober and Ariew have recognized that old accounts of innateness, such as that of Konrad Lorenz were too rigid. They could not account for cases such as PKU disease or Sober’s birdsong example. However, it appears that their accounts are too liberal.

4.3 Richard Samuels’ Primitivism

In his forthcoming article Richard Samuels rightly notes that canalization and Sober’s invariance account try to capture a mapping from genotype to phenotype, but fail to put any constraints on the mechanisms that account for that mapping. The most simplistic mapping of genotype to phenotype occurs in Konrad Lorenz’s innateness account. For Lorenz (1953) , an innate trait is one that is genetically transmitted as opposed to acquired through learning. This is the account that everyone has been reacting against since. Griffiths & Gray (1994) subject this account of traits being genetically programmed to a devastating critique. Further, there are all kinds of problem cases for his account such as PKU and Sober’s birdsong example. These are problematic for Lorenz because a good account of the development of the birdsong and the appearance of the deleterious effects of PKU requires reference to environmental factors as well as genes. Ariew and Sober try to solve this problem by treating innateness as a continuum rather than a dichotomy. However, these accounts still map genotype to phenotype and are subject to the problems mentioned above because of this. Samuels’ solution is to cut Lorenz’s innateness in half. Since it is the genes that are the problem, reasons Samuels, I will cut out the genetic transmission part. What we are left with is that a cognitive trait is innate just in case it is not learned. This is roughly what Samuels proposes. As will shortly become apparent this puts innateness purely in the realm of psychology and removes it from all other fields of inquiry. This, I will show, is still too liberal for our explanatory needs in one sense and in another sense far too restrictive. What results is a concept that still exemplifies problems similar to those discussed above.

4.3.1 Desiderata and Primitivism

Before considering these problems I will briefly review Samuels’ desiderata for innateness and the resulting account. The desiderata are as follows.

1. The Fundamental Conceptual Constraint- “If a cognitive structure is innate, then it is not learned.” (Samuels forthcoming, p. 3) This constraint ends up being nearly identical with innateness on Samuels’ account. Samuels argues that it is failure to meet this constraint that explains the failings of Sober and Ariew’s innateness accounts.

2. The Negative Conceptual Constraint- “The claim that a cognitive structure is innate does not imply that no environmental factors contribute to the acquisition of the structure.” (Samuels forthcoming, p. 4) The problem is to make explicit what constraints if any apply to the environment’s causal contributions to development. Samuels leaves his innateness account neutral on this issue. He provides no constraints one way or the other. Sober uses a “a range of environments” clause in his account in order to place a constraint on environmental contribution and is lead to an overgeneralization problem. Similarly Ariew characterizes canalization in part as “insensitivity to a range of environments” with the same result.
3. The Argument constraint. The idea here is that the account of innateness ought to allow arguments for innateness prima facie plausibility.

4. The Logical Geography Constraint- An innateness account should categorize prototypical nativists such as Chomsky and Fodor as nativists and it should categorize prototypical empiricists such as Skinner and Piaget as empiricists. No argument here.

5. The Significance Constraint- An innateness account should make it apparent ceteris paribus why nativism matters to cognitive scientists. I will argue below that cognitive scientists interested in developmental explanations of traits should probably not think that nativism matters. Further, the notion may well be destructive.

Given this set of desiderata Samuels concludes that “a psychological structure is innate just in case it is a psychological primitive.” (Samuels forthcoming, p. 14) Samuels leaves “psychological structure” undefined, but he does provide us with the following examples: concept, belief, learning mechanism or module. A psychological structure is a psychological primitive just in case:

“1. S is a structure posited by some correct scientific psychological theory.
2. There is no correct scientific psychological theory that explains the acquisition of S (in the baseline sense of “acquisition”).” (Samuels forthcoming, p. 13)

Samuels gives us a cluster of inductive learning theories of concept acquisition as an example of what would count as a correct scientific psychological account of a psychological structure’s acquisition. In other words, any trait that is learned cannot be innate and conversely any trait that is innate is not learned. “So, I am happy to view primitivism (at least for the moment) as an articulation of the appropriate sense in which innate cognitive structures are not learned.” (Samuels forthcoming, p. 17). This comes with the caveat that learning should be broadly construed and that a normalcy clause, which I will discuss later, will have to be added. It seems very unsatisfactory that innateness turns out to be just a negative characterization. After all there are many ways ‘not’ to be something. The account doesn’t seem to tell us much. However, if innateness is characterized merely as not learned then we need to know what Samuels has in mind for learning.

4.3.2 Primitivism is too Liberal

In order for innateness as Samuels’ construes to have any explanatory contrast we need to know what counts as learning. Once we know what learning is then we can identify traits as innate and perhaps learn something about their ontogeny or development. Below we will see that Samuels’ notion of learning leads to an overgeneralization problem. Also, we will also see an overgeneralization problem akin to those suffered by Sober and Ariew’s accounts.
Samuels wants to avoid accounts of learning that would be too restrictive on his account. Here notes two notions of learning that are too restrictive. “1. It is not uncommon to preclude various perceptual processes such as visual processing from counting as forms of learning, even though they are psychological processes of acquisition. 2. Similarly, it is common for cognitive scientists to characterize learning as on inferential process whereby stimuli are used as evidence in the formation of concepts or knowledge structures.” (Samuels forthcoming, p. 17) Given that Samuels doesn’t want to preclude “visual processing” from learning and the fact that Samuels will accept connectionist theories as scientific psychology gives us an interesting case of over-generalization.
Ralph Linsker (Linsker 1988) created a connectionist network that models the way someone might development basic features of vision such as edge detection. The idea in visual science is the visual system is organized into a set of layers that process successively more complex features of the visual world. The first layer consists of two types of cell organization on the retina. These cells groups have excitatory regions and inhibitory regions that are sensitive to light. Some cell groups are sensitive in the center and inhibitory in the surround while others are sensitive in the surround while inhibitory in the center. (see fig. 1 below).

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In the next layer cell groups of the same type can be lined up, as it were, in order to detect light edges or dark edges as needed. At this layer the cells may be more sensitive to horizontal bars or vertical bars. Linsker was able to create a feed-forward network that self-organized so as to realize these edge detectors. The only input that was needed was some random light noise. The self organization into these edge detectors occurred by virtue of the interaction of the network architecture and this random noise from the environment.
The point is, if it is the case that our actual visual system develops in the same way, then under Samuels account we will have to say that the development of our visual capacity to detect edges is learned and thus not innate. Hebbian learning and back propagation would count as learning under Samuels view because he does not want to place the limitation quoted above on what counts as learning. This is a highly counter-intuitive result. The development of something as basic and fundamental to vision as edge detection should surely be regarded as innate. One might argue that this model can be seen as a model of some brute causal process whereby random light entering the visual system causes neural reorganization. However, Samuels has not precluded this from counting as learning in cases where this neural reorganization is construed as Hebbian learning mediated by back propagation. It simply isn’t clear on Samuels account where to draw the line between a psychological processes and a neurological processes.

There is another sense in which Samuels’ account is too liberal. This time it is the innateness rather than learning that is given too broad a scope. Samuels is aware of the following over-generalization problem and offers some possible solutions which will be discussed later. Samuels mentions the possibility of there being something like a Latin pill. A Latin pill would be one that a person could just swallow and subsequently changes in their neurochemistry would occur such that they now have the ability to speak Latin fluently. Swallowing a pill is certainly not a psychological process and would be a psychological primitive; therefore, the knowledge of Latin would have to counted as innate in this case. This version of overgeneralization is not too worrying, because it is highly unlikely if not impossible that this situation will ever occur. Since it is unlikely there will be such a thing as a Latin Pill, this problem is not too much of a worry for Samuels account. His account is not meant to be a conceptual analysis of the term innate and it is to be understood as a defensible account. A more problematic version of overgeneralization occurs when pathologies cause one to acquire new cognitive traits. Samuels mentions a disease in Australia called Ross River fever, that causes its victims to hallucinate that buildings are crashing down. This disease is spread by mosquitoes. Thus we have a new cognitive trait that is not acquired via a psychological process and must be counted as innate. Samuels also mentions the possibility of lesions inflicted on somebody’s brain by some horrific accident. It might be that someone acquires some strange new cognitive trait as seeing a red patch in their visual field all the time.
Since primitivism places no constraints on environmental contributions, it suffers from this overgeneralization problem. We get on one extreme Lorenz’s the view that nothing from the environment can be involved in the development of an innate trait. On the other end of the spectrum we get an account that says nothing about the way environmental factors effect the development of a trait. Samuels account puts no constraint on environmental contribution at all. Samuels notes that all of the counter-examples to his case seem to be pathological in nature and this leads him to adopt a problematic normalcy clause.

4.3.3 Primitivism is too Restrictive

In his discussion of what should count as a scientific psychology, Samuels rightly recognizes innateness ought to be a term that helps to explain the ontogeny or development of these cognitive traits. He also recognizes that the other type of explanation common to these debates is evolutionary explanation and he gives a very good reason to reject this sort of explanation with regard to innateness. “What primitivism maintains is that if a cognitive structure S is innate, then scientific psychology can specify no mechanism or process in virtue of which S is possessed by an individual organism O at a given time t, even though there is no time prior to t at which P possesses S. But evolutionary theories -whether adaptationist or not- simply do not address this question.” (Samuels forthcoming p. 18) He points out the developmental theories do address this issue.
The complaint I have been making against all of these accounts is that they don’t provide any constraints on the mechanisms of development. These accounts only say something about the outcomes and not how that outcome comes about. Samuels account doesn’t tell us anything positive about the developmental mechanism that produces these cognitive traits. He has given us a hint at what developmental mechanism is not involved, namely learning. This doesn’t tell us much because there is a severe lack of learning theories out there and it is not clear precisely what would count as learning. As I said above if innate traits are not learned traits then we need to know what learning is.
Eliminating discussion of innateness from all fields except psychology is all well and good for the psychologist, but what help is it for the neurobiologist. This artificial division away from biology contributes to the overgeneralization problem discussed above. If innateness precludes psychological explanation then it should give us a constraint on the biological end of development. However the only constraint Samuels does place on the biology of development is his normalcy clause. Simply that everything happening in development ought to go normally. “Normalcy Condition. A (token) cognitive structure S possessed by an organism O is innate only if O would acquire S (in the baseline sense) in the normal course of events.”(Samuels forthcoming p. 25) Samuels invokes this normalcy clause in order to account for the pathological counter-examples to his account discussed above. This “normal course of events” is precisely what a developmental account of acquisition is supposed to explain. When we give an account of development we give a history of the causal factors or mechanisms that produces the trait in question. The normal course of events is precisely this set of causal factors. Adopting this normalcy clause combined with limiting innateness to psychological explanation is downright destructive to the scientific enterprise. What kind of evidence could we have that something is not learned? The standard practice in ethology is to perform deprivation experiments. Limit features of an animal’s environment and note whether that animal still acquires the trait in question. This of course would not be the normal course of events. For Samuels this test would not count as evidence of innateness, rather it would just be as case of pathology akin to Ross River fever or a nasty knock on the head. Just as the pathological cases could be deemed not normal, so would any experimental manipulation that a scientist might perform on the developmental environment. Samuels actually criticizes evidence sited by Elman et al (1996) in their plasticity argument on this very point. The nature of evidence was invasive experimental manipulation on the brains of animals. Perhaps Samuels would not count ethology as scientific psychology since its subject is animals rather than humans. To suggest that a concept that is supposed to play some explanatory role in development should only belong to the discipline of psychology is counter-productive. A great source of experimental evidence about development comes from comparing human development with that of our close evolutionary cousins. Nevertheless suppose that it is the case that Samuels really intends there to be such a restriction. Then we could not count pathological conditions that arrive in humans by some horrible accident as evidence one way or another for innateness, because these would not count as normal conditions. If we are to adopt such a normalcy clause for innateness then we rob ourselves of a very important source of evidence and a very important scientific methodology. Samuels’ account is so restrictive in this sense, that it inhibiting and destructive to the scientific enterprise of trying to understand the development of cognitive traits.

5. Conclusion

We have seen that there don’t seem to be any adequate developmental accounts of innateness on offer. Fiona Cowie fails to make the distinction between what’s innate and what innateness is. Sober, Ariew, and Samuels fail to sufficiently recognize the distinction between explanatory projects. Since many claims of innateness in cognitive science seem to be developmental claims we wanted an account of innateness that was a developmental account. A developmental account would put constraints on the mechanism in an individual that produces a particular outcome rather than on the about the distribution of that outcome. It is interesting to note that the accounts I reviewed above all had problems with overgeneralization. This can be diagnosed as a failure to find good constraints on the environmental contribution to innateness. Sober and Ariew try to constrain environmental contribution by making reference to a range of environmental conditions without giving us any principled way to identify the relevant range of environments. Samuels places no constraint whatsoever on the environmental contribution to development. If a satisfactory constraint cannot be found, innateness as a developmental concept will join superlunary space in the rubbish bin of useless concepts. We have seen that the behavioral geneticists notion of heritability serves nicely in evolutionary explanation. It may well be that heritability is the only useful notion of innateness available, but it should be kept clear that this notion will only function for adaptive evolutionary explanation and is not a useful concept for developmental explanation.

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Copyright © 2002 Christopher Jenson. All rights reserved