Determinaci´on de velocidades de consumo

Arguments in support of nativism typically consist of two threads involving a negative and a positive thesis. The negative thesis involves the denial of domain-general learning as a plausible explanation for the acquisition of the trait in question. If domain-general learning cannot account for acquisition, then we are led towards a nativist conclusion (Cowie 1999). The positive thesis involves positing the requisite innate, species-universal acquisition mechanism with which to account for the particular trait. The negative and positive theses can be seen at play in the paradigm nativist case, language. Chomsky’s famous poverty of the stimulus argument is based on the claim that there is inadequate data in the environment for a child to learn the complexities of language required to achieve mature competence. Therefore, the requisite data must be innate. This data comes in the form of a universal grammar which specifies the structural information required for language acquisition in the impoverished environment (Chomsky 1986;

Pinker 1994).

The poverty of the stimulus family of arguments draws attention to a supposed

explanatory problem: that our experiential input is inadequate to account for particular mental resources that we have. There is nothing in our experience that could account for some of our cognitive abilities so we must appeal to some form of innate, domain-specific information or structure. Poverty of the stimulus arguments combine claims about development and task analysis with respect to a particular task- or domain- specific activity (Sterelny 2003):

• The developmental claim relates to the ontogenic expression of a particular mature competence in question – although dependent on information to trigger expression, it is relatively independent of variance in informational exposure:

change in developmental environment does not necessitate a difference in development of competence.

• The task analysis claim “takes mature competence in the focal domain to rest on a theory of that domain, and argues that the task of generating a theory from perceptual evidence is an excessively challenging one” (Sterelny 2003:195). The move from perceptual data to theory formation can only be accounted for via innate faculties.

Recently, philosophers and psychologists have drawn strong analogies between language and morality. These ‘moral grammarians’ have exported aspects of the Chomskyian linguistics research programme to the domain of morality. Here again, we see the negative and positive threads of the nativist argument. The moral grammarians claim that the informational exposure in the environment is inadequate to explain moral competence through domain-general learning alone. The gap between informational exposure on the one hand and achieved moral competence on the other cannot be bridged by domain-general learning mechanisms and the environmental resources available to the moral learner. Therefore, some form of innate moral information or structure must be posited to bridge the gap between exposure and competence. This is the crux of the poverty of the moral stimulus (POMS) argument. Analogously, they also argue that there is an underlying Universal Moral Grammar, based upon the Principle and Parameters model in linguistics, which can explain the universality, diversity, compositionality, and computational nature of moral acquisition and competence (Dwyer 1999, 2006; Harman 2000, 2008; Mikhail 2002, 2007; Hauser 2006a, 2006b; Hauser,

Young et al. 2008b).

Although the focus of this chapter will be on acquisition, the structure of moral competence is relevant. How much evidence is required in the learning environment will depend on what one has to learn, because the possibility of moral competence through learning will depend in part on the nature of that competence. If, for example, one thinks that moral competence involves the possession of abstract principles, as the moral grammarians do, then the learning environment needs to contain the relevant information to learn those principles. If the learning environment is impoverished with respect to this information, the innate components of the moral mind must contain the relevant information. One of the reasons for focusing on acquisition in this chapter is that the POMS argument is not confined to specific structural claims of the moral grammarians. It is endorsed, in some form, by all moral nativists (see for example, Joyce (2006)). (For detailed criticism of the structural parallels between language and morality see Dupoux and Jacob 2007.; See also Prinz 2008a; Sripada 2008a; Sterelny forthcoming.)

Box 2.0 Against the poverty of the moral stimulus

Since the advent of the poverty of the moral stimulus argument there have been a number of critiques directed at it on both empirical and theoretical grounds. Shaun Nichols (2005) argues that domain diverse emotions play a special role in generating non-conventional judgements (including moral judgements). Jesse Prinz (2008a, 2008c) looks at the role that emotional consequences of norm violations and the differences in the enforcement of moral and conventional norms play in the moral acquisition process.

These he argues, provide sufficient learning resources for the non-nativist moral child.

Chandra Sripada (2008a, 2008b) maintains that compared to language acquisition, the learning target in moral learning is less complex. He also argues that moral learning, unlike language learning, need not be inductive; it often involves explicit instruction, whereas language learning does not.

I will, among other things, provide further analysis of these ideas as well as the implications of further empirical evidence on the poverty of the moral stimulus argument.

The acquisition argument, in the form of poverty of the stimulus arguments, has been, either implicitly or explicitly, central to recent defences of moral nativism.⁴ A significant piece of evidence cited in support of the POMS relies on the early emergence of sensitivity to a distinction between moral and conventional rules. Evidence for the moral/conventional distinction came from research into social domain models of social cognition, in which morality was identified as a distinct developmental and conceptual domain (cf. domain-specificity above). All children, except those with psychopathic disorders, show proficiency at drawing the distinction from an early age along the same dimensions as adults do. Moral norms are typically identified as more authority independent, more generalisable, more serious than conventional norms, and justifications in the moral domain typically appeal to issues of harm and welfare. Children show this ability at an early age, some younger than three years old. (Turiel 1983; Turiel 1998; Smetana 2006; Tisak, Tisak et al. 2006).⁵ This is taken as evidence by the proponents of the POMS argument that firstly, morality is a distinct domain of social knowledge, and secondly, that children’s proficiency at this task indicates that moral competence comes on-line at an early age, a level of competence beyond anything that the child has been taught (Dwyer 2006; Hauser 2006a, 2006b; Joyce 2006; Mikhail 2008b). I will argue below that the evidence offered by the nativist in support of the POMS argument, including proficiency at the moral/conventional distinction, is not adequate to establish the argument for nativism.

In terms of the developmental claim, the POMS argument asserts that moral competence comes on early in life, too early to be explained by reference to the information exposure that children receive. Further, moral development is invariant to differences in moral information exposure in the child’s environment. All normal children attain moral competence in varying moral environments. With respect to task analysis, the POMS argument makes two claims. Firstly, a child’s moral learning environment is noisy; it is awash with norms that are not explicitly nor adequately identified as moral or

4. From here on, I will understand the term ‘moral nativist’ to refer to those who employ the poverty of the moral stimulus argument. It is an interesting and open question as to whether all nativist arguments necessarily employ poverty of the stimulus type arguments, but not a question that will be addressed here.

5. It should be noted that some authors have recently questioned the moral/conventional distinction.

Kelly and Stich (2007; Kelly, Stich et al. 2007) point out that the class of transgressions over which it has been tested has been very narrow. They provide evidence that the distinction is not robust over a larger class of transgressions. This seriously questions the basic datum of the moral nativists who appeal to the moral/conventional distinction in support of nativism. See also Prinz (2008a).

conventional, so the evidence is inadequate to explain the acquisition of the capacity to draw the moral/conventional distinction. Therefore, the information available to the child from the environment alone is impoverished. Secondly, the complexity of the learning task is especially difficult because “to solve it one must identify a class of considered moral judgements and a set of principles from which they can be derived”

(Mikhail 2008b:353-354). The task of rule extraction from the surrounding environmental data is too complex to be accounted for in terms of empiricist learning alone because “empiricist accounts radically underestimate the complexity of the task that faces the young child with respect to rule recovery” (Dwyer 2006:239). Moral nativists also often claim that the principles that guide our moral behaviour are unconscious and cognitively inaccessible, and therefore unlikely to have been learned.

(As I will explain in section 2.4.3 below, I see this last claim as being, in part, about the complexity of the learning task.) In summary, we have an informational gap that is due to both the inadequate resources available to a non-nativist moral learner and the complexity of the moral learning task. According to the nativist, this gap between informational input and behavioural output can only be bridged by some form of innate, domain-specific, information or mechanism – i.e., the said moral faculty.

I will now argue against the POMS argument by looking at both the developmental and task analysis claims, showing that the moral stimulus is not impoverished; there is no gap between the informational input of experience and the output of behaviour. Before moving to this analysis, there is an important point to note with respect to a non-nativist account of moral acquisition: there are no constraints on the nature of the inputs and cognitive mechanisms of moral acquisition except that the internal cognitive resources must not be specific to the moral domain. In other words, any non-moral cognitive capacities (be they innate or otherwise) and any external (including moral) resources can freely operate as inputs and mechanisms in the acquisition process. To this extent, the moral non-nativist need not claim that the mind is a tabula rasa, only that the moral mind is.