Dual-Process Theory of Cognitive Development
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This section introduces two questions and a dual-process theory of cognitive development.
Why Do Different Responses Reveal Different Developmental Patterns?
Physical objects cannot pass through impenetrable barriers. Infants demonstrate sensitivity to this fact from around three months of age (see, for example, Spelke, Breinlinger, Macomber, & Jacobson, 1992 or Baillargeon, 1987 for two classic studies using habituation). There is also evidence for sensitity to this fact in chimpanzees (Cacchione & Krist, 2004) and dogs (Kundey, Reyes, Taglang, Baruch, & German, 2010).
The infant studies just mentioned use looking-time responses, as in habituation or violation-of-expectation paradigms. But what if we instead measure infants’ manual searching to determine when they are first sensitive to the impossibility of physical objects passing through impenetrable barriers? It turns out that 2.5- and 3-year-olds struggle on a simple search task (Berthier, De Blois, Poirier, Novak, & Clifton, 2000; Hood, Cole-Davies, & Dias, 2003). Indeed, using the same stimuli, children can demonstrate competence in tracking causal interactions on violation-of-expectations and anticipatory looking measures while systematically failing to manifest competence in their searching (Mash, Novak, Berthier, & Keen, 2006).
Different responses indicate different developmental patterns. When observing looking times in habituation or violation-of-expectation paradigms, we do not see developmental changes around the third year of life. But when observing searching behaviours we see gradual changes around the third year of life.
This is true not only for sensitivity to physical principles. It also applies to sensitivity to facts about others’ minds. Studies of mindreading regularly find that different responses indicate different developmental patterns (see, for example, Low & Watts, 2013; the earliest study on this is Clements & Perner, 1994).
Why do different responses reveal different developmental patterns? (Or, as I put it in the talk, Why is there an interaction with age?)
The Differences Are Not a Quirk
One tempting idea is that measures based on looking times are simply more sensitive. The appearance that other measures (verbal responses or manual search) reveal developmental changes is an illusion. They are merely noisier measures.
This is unlikely because in a range of tasks looking-time measures fail to reveal knowledge that manual search and verbal responses do demonstrate (see Low & Watts, 2013 on mindreading or Charles & Rivera, 2009 on object tracking, for example).
Researchers have mostly treated evidence that different responses reveal different developmental patterns as a methodological quirk. This has led to explanations that are specific to one domain. Even if one such explanation were convincing, we should wonder why the pattern of differences arises in multiple domains.
Suppose we treat the fact that different responses reveal different developmental patterns as a key bit of data, rather than as a quirk. Then we are led to a dual-process theory of cognitive development.
A Dual-Process Theory of Cognitive Development
Before stating the theory we need the notion of a fast process:
One process is faster than another: it makes fewer demands on scarce cognitive resources such as attention, inhibitory control and working memory.
The theory states:
This theory is in the spirit of views about core knowledge (Carey & Spelke, 1996) but without commitments concerning what (if anything) is represented, innateness of phylogeny.
Why Different Responses Reveal Different Developmental Patterns
It is because some responses are mainly reflect the operations of faster processes, which are relatively unchanging and largely immune to learning and culture, whereas other responses are dominated by slower processes, which do change across development through learning.
Predictions of The Dual-Process Theory
The dual-process theory makes a prediction about commonalities between infants and adults:
Where infants can track objects or beliefs, in adults there will be two distinct processes and one adult process will have features in common with the infant process.
How Could Fast Processes Influence Looking Duration?
Observations that reveal early sensitivity to others’ minds, and to causal interactions, typically involve differences in looking times of around 10–20 seconds. It is unclear how fast processes could explain these. Indeed, the suggestion that they do appears to be post-hoc. From the way fast and slow are distinguished, the differences in looking times might equally well be attributed to slow processes.
So it seems that the dual-process theory of cognitive development does not work after all. Apparently, the theory cannot explain why different responses reveal different developmental patterns.
In what follows we will see that by adding metacognitive feelings we can make the dual-process theory succeed.
Since automaticity and cognitive efficiency are matters of degree, it is only strictly correct to identify some processes as faster than others.
The fast-slow distinction has been variously characterised in ways that do not entirely overlap (even individual author have offered differing characterisations at different times; e.g. Kahneman, 2013; Morewedge & Kahneman, 2010; Kahneman & Klein, 2009; Kahneman, 2002): as its advocates stress, it is a rough-and-ready tool rather than an element in a rigorous theory.
There is an issue about replication, on which a variety of views have been offered. Evidence gathering is ongoing (see manybabies2 and their pre-registered publication). My guess, based on currently mixed patterns of success and failure in replication attempts, is that although some individual findings do not reliably replicate, we will see that different responses indicate different developmental patterns (as I explain in Chapter 12.3 of Butterfill, 2020). ↩︎
Compare Frankish & Evans (2009, p. 1): ‘These theories come in different forms, but all agree in positing two distinct processing mechanisms for a given task, which employ different procedures and may yield different, and sometimes conflicting, results.’ ↩︎