Link Search Menu Expand Document

Davidson’s Challenge

Lecturer: Stephen A. Butterfill

There is an obstacle to understanding the emergence of knowledge in development. As Davidson (1999, 11) puts it, ‘We have many vocabularies for describing nature when we regard it as mindless and we have a mentalistic vocabulary for describing thought and intentional action what we lack is a way of describing what is in between.’

My aims in this section are to explain why studying development involves facing broadly philosophical problems, and to introduce one of the central problems.

Slides

What Is Knowledge?

I start with two uncontroversial premises about knowledge.

First, knowledge is constitutively linked to practical reasoning and to inference. It is the kind of thing that can typically influence how you act when you act purposively, and it is the kind of thing that can influence purposive actions in any domain at all. Knowledge is also the kind of thing that you can sometimes arrive at by inference, and which can enable you to make new inferences in any domain at all.

Second, knowledge states are inferentially integrated with other attitudes like beliefs, desires and intentions.

Uncomplicated Account of Minds and Actions

For any given proposition [There’s a spider behind the book] and any given human [Wy] …

  1. Either Wy believes that there’s a spider behind the book, or she does not.
  2. Either Wy can act for the reason that there is, or seems to be, a spider behind the book, or else she cannot.
  3. The first alternatives of (1) and (2) are either both true or both false.

Discoveries about how abilities to track unperceived objects develop form a pattern sometimes described as paradoxical. This is because those discoveries conflict with the Uncomplicated Account.

Unperceived Objects

When do humans first come to know facts about the locations of objects they are not perceiving? (This ability is sometimes called object permanence.)

The answer depends on how we measure their abilities:

look (habituation): by 4 months of age or earlier (Baillargeon, 1987).

look: by around 2.5 months of age or earlier (Aguiar & Baillargeon, 1999, p. Experiment 2)

search: not until after 7 months of age (Shinskey & Munakata, 2001)

Could the discrepancy be entirely due to infants’ difficulties performing actions? Probably not: ‘action demands are not the only cause of failures on occlusion tasks’ (Shinskey, 2012, p. \ 291).

In short,

‘violation-of-expectation experiments, using looking-time measures, suggested that infants have object permanence in occlusion conditions; but simplified-search studies confirm that infants fail to reach towards occluded objects, suggesting that infants do not have object permanence in occlusion conditions. This discrepancy, however, is only the tip of the iceberg. Results of studies attempting to measure infants’ cognitive abilities using reaching measures often contradict results gained while using looking-time measures’ (Charles & Rivera, 2009, p. \ 994).

Davidson’s Challenge

‘if you want to describe what is going on in the head of the child when it has a few words which it utters in appropriate situations, you will fail’ (Davidson, 2001, pp. 127–8).

‘The difficulty in describing the emergence of mental phenomena is a conceptual problem […] In […] the evolution of thought in an individual, there is a stage at which there is no thought followed by a subsequent stage at which there is thought. To describe the emergence of thought would be to describe the process which leads from the first to the second of these stages. What we lack is a satisfactory vocabulary for describing the intermediate steps’ (Davidson, 2001, p. 127).

‘We have many vocabularies for describing nature when we regard it as mindless, and we have a mentalistic vocabulary for describing thought and intentional action; what we lack is a way of describing what is in between’ (Davidson, 1999, p. \ 11)

Core knowledge

Some researchers have proposed that understanding the developmental emergence of knowledge requires postulating novel kinds of mental state. In this course we will focus on proponents of core knowledge:

‘there is a third type of conceptual structure, dubbed “core knowledge” … that differs systematically from both sensory/perceptual representation[s] … and … knowledge’ (Carey, 2009, p. 10).

There are also more radical suggestions:

‘there are many separable systems of mental representations … the task … is to … [find] the distinct systems of mental representation and to understand their development and integration’ (Hood, Carey, & Prasada, 2000, p. \ 1522).

Does understanding developmental require postulating novel kinds of mental state?

Glossary

core knowledge : For an individual to have core knowledge concerning a domain such as physical objects, actions or minds is for her to have a core system specifically for this domain. For someone to have core knowledge of a particular principle or fact is for her to have a core system where either the core system includes a representation of that principle or else the principle plays a special role in describing the core system. Core knowledge is not knowledge, and you can have core knowledge of things that are untrue (for this reason Carey (2009, p. 10) recommends the term ‘core cognition’ for states of core knowledge).
core system : This course uses a nonstandard, minimally informative notion of core system on which a ‘core system’ for a particular domain is simply whatever it is that underpins the earliest abilities infants manifest in that domain (see \cref{sec:core-knowledge-minimal-view}). This allows that core systems may lack uniformity across domains and unity within a domain: that is, different kinds of system may qualify as ‘core’ in different domains, and a core system may comprise two or more largely distinct systems (see \cref{sec:paradox-lost}).
However, core systems are standardly identified by giving a list of features. The lists vary between researchers and times. Carey & Spelke (1996, p. 520) assert that core systems are largely innate, informationally encapsulated (that is, their operations are largely unaffected by things you know or believe, and by core knowledge in other core systems), largely unchanging over the course of development (so adults and infants alike have the same core systems). They also say that the inputs to core systems are the outputs of perceptual systems, so that architecturally core systems in human adults occupy a position between perception and knowledge. Finally, core systems are also held to arise from systems already present in the evolutionary ancestors of modern humans. Carey (2009) adds that the representations in core systems are iconic representations.
habituation : Habituation is used to test hypotheses about which events are interestingly different to an infant. In a habituation experiment, infants are shown an event repeatedly until it no longer holds their interest, as measured by how long they look at it. The infants are then divided into two (or more) groups and each group is shown a new event. How much longer do they look at the new event than at the most recent presentation of the old event? This difference in looking times indicates dishabituation, or the reawakening of interest. Given the assumption that greater dishabituation indicates that the old and new events are more interestingly different to the infant, evidence from patterns of dishabituation can sometimes support conclusions about patterns in how similar and different events are to infants.
inferential integration : For states to be inferentially integrated means that: (a) they can come to be nonaccidentally related in ways that are approximately rational thanks to processes of inference and practical reasoning; and (b) in the absence of obstacles such as time pressure, distraction, motivations to be irrational, self-deception or exhaustion, approximately rational harmony will characteristically be maintained among those states that are currently active.
object permanence : the ability to track objects while briefly unperceived.

References

Aguiar, A., & Baillargeon, R. (1999). 2.5-month-old infants’ reasoning about when objects should and should not be occluded. Cognitive Psychology, 39, 116–157.
Baillargeon, R. (1987). Object permanence in 3.5-and 4.5-month-old infants. Developmental Psychology, 23(5), 655–664.
Carey, S. (2009). The origin of concepts. Oxford: Oxford University Press.
Carey, S., & Spelke, E. S. (1996). Science and core knowledge. Philosophy of Science, 63, 515–533.
Charles, E. P., & Rivera, S. M. (2009). Object permanence and method of disappearance: Looking measures further contradict reaching measures. Developmental Science, 12(6), 991–1006. https://doi.org/10.1111/j.1467-7687.2009.00844.x
Davidson, D. (1999). The emergence of thought. Erkenntnis, 51, 7–17.
Davidson, D. (2001). Subjective, intersubjective, objective. Oxford: Clarendon Press.
Hood, B., Carey, S., & Prasada, S. (2000). Predicting the outcomes of physical events: Two-year-olds fail to reveal knowledge of solidity and support. Child Development, 71(6), 1540–1554.
Meltzoff, A. N., & Moore, M. K. (1998). Object representation, identity, and the paradox of early permanence: Steps toward a new framework. Infant Behavior and Development, 21(2), 201–235.
Moore, M. K., & Meltzoff, A. N. (2008). Factors affecting infants’ manual search for occluded objects and the genesis of object permanence. Infant Behavior and Development, 31(2), 168–180. https://doi.org/10.1016/j.infbeh.2007.10.006
Shinskey, J. L. (2012). Disappearing décalage: Object search in light and dark at 6 months. Infancy, 17(3), 272–294. https://doi.org/10.1111/j.1532-7078.2011.00078.x
Shinskey, J. L., & Munakata, Y. (2001). Detecting transparent barriers: Clear evidence against the means-end deficit account of search failures. Infancy, 2(3), 395–404.