The Core Idea

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The Core Idea

s.butterfill@warwick.ac.uk & c.sinigaglia

notes on our web page

http://two-systems.sinigaglia.and.butterfill.com/

approximate timing

11.05 -- 11.40 : 35 minutes lecture (ask questions at any point)

11.40 -- 11.55 : 15 minutes discussion

11.55 -- 12.05 : 10 minutes break

12.05 -- 12.40 : 35 minutes lecture (ask questions at any point)

12.40 -- 12.55 : 15 minutes discussion

What does it mean to say that there are two systems?

In one domain there are two (or more) processes with potentially conflicting outputs.

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.’

minimal illustration

What do you compute that enables you to track toxicity?

Option 2 (slow but accurate) : measure molecular composition (feed it to shellfish and use liquid chromatography-mass spectrometry)

Option 1 (limted but fast) : experience disgust

‘Disgust [...] originated in [...] a food-rejection impulse or motivation triggered by the ingestion of [...] substances [...] that are bitter. Because many bitter substances are toxic, [..] distaste [...] has a clear [...] adaptive function.

Distaste appears to have very ancient origins: Even sea anemones, which first evolved some 500 million years ago, will expel bitter foods from their gastric cavity’

(Chapman & Anderson, 2013, p. 300)

Two Systems Theory of Toxicity (core part)

Two (or more) processes for tracking toxicity are distinct:
the conditions which influence whether they occur,
and which outputs they generate,
do not completely overlap.

One process makes fewer demands on scarce cognitive resources than the other.

(Terminology: fast vs slow)

Start with a simple causal model.

‘response 1’ is a variable representing which response the subject will give. [Which values it takes will depend on what sort of response it is (e.g. a verbal response, proactive gaze, button press.) We can think of it as taking three values, one for correct belief tracking, one for fact tracking, and one for any other response.]

‘process 1’ and ‘process 2’ are variables which each represent whether a certain kind of DOMAIN process will occur and, if so, what it’s outcome is.

And the arrows show that the probability that response 1 will have a certain value is influenced by the value of the variables process 1 and process 2 (and by other things not included in the model). So it should be possible to intervene on the value of ‘process 1’ in order to bring about a change in the value of ‘response 1’.

[I’ve used thicker and thinner arrows informally to indicate stronger and weaker dependence. Strictly speaking the width has no meaning and this model doesn’t specify exactly how the values of variables are related, only that they are.]

Two Systems Theory of X (core part)

Two (or more) processes concerning X are distinct:
the conditions which influence whether they occur,
and which outputs they generate,
do not completely overlap.

One process makes fewer demands on scarce cognitive resources than the other.

(Terminology: fast vs slow)

Ok, that’s what the theory says. But what does it mean?

So far I’ve been working with a simplifying assumption about the relation between types of response and kinds of process.

Process 1 -> Response 1

Process 2 -> Response 2

I’ve been assuming that responses of type R1 are dominated by one mindreading process whereas responses of type R2 are dominated by another mindreading process. But responses types and processes may not be so closely associated, of course.

This is because (a) any response is likely to be a consequence of multiple processes; and, (b), for some response types such as button selection or proactive gaze, changing factors like time pressure could change which mindreading process dominates responses of that type.

In fact variability in the relation between a mindreading process and a response type is a potentially useful source of evidence in support of a dual process theory of mindreading. Changes in the processes determining a response type can be detected where we have situations in which we know, or assume, the two processes yield different answers (cf Todd et al). For example ...

To illustrate, take the case where we instruct subjects to track the location of a ball. Subjects are asked to press a button to indicate whether a ball is present or absent. We know that button selection will not track beliefs when subjects are not under time pressure. But what happens if we increase time pressure.

It is possible that increasing time pressure will very slightly, but perhaps measurably increase the probability that button presses are dominated by a different mindreading process, one that is less sensitive to instructions. In that case, we would expect to observe slightly more belief tracking in the responses as time pressure is increased.

Todd, Cameron, & Simpson (2016) have recently demonstrated this type of effect for L1-VPT; as far as I know, it has not yet been demonstrated for belief tracking.

Two Systems Theory of X (core part)

Two (or more) processes concerning X are distinct:
the conditions which influence whether they occur,
and which outputs they generate,
do not completely overlap.

One process makes fewer demands on scarce cognitive resources than the other.

(Terminology: fast vs slow)

Two Systems or Dual Process?

‘We use the term “system” only as a label for collections of cognitive processes that can be distinguished by their speed, their controllability, and the contents on which they operate’ (Kahneman & Frederick, 2005, p. 267).

Gawronski, Sherman, & Trope (2014) do distinguish dual process from two systems theories

domains

In Which Domains Are There Two-Systems Theories? Two-systems theories of one kind or another have been proposed for various domains. Here is a partial list of domains (note that some domains may overlap):

reasoning and inference (Evans, 2003)
judgement and decision-making (Kahneman, 2002)
memory (Jacoby, 1991)
social cognition (Gawronski et al., 2014)
mindreading (Apperly & Butterfill, 2009)
number (Feigenson, Dehaene, & Spelke, 2004)
ethics (Greene, Nystrom, Engell, Darley, & Cohen, 2004)
instrumental behaviour (Dickinson & Pérez, 2018)
learning (Dayan & Berridge, 2014)

There are also domains where it is arguably coherent to suppose that researchers have identified what might be called a two-systems theory although this terminology is not in common use:

? social norms (Bicchieri, 2016)
? physical cognition (Kozhevnikov & Hegarty, 2001)
? categorical colour (Gilbert, Regier, & Ivry, 2006)
? vision (Goodale & Milner, 1992)
? agency (Sidarus, Vuorre, & Haggard, 2017)

dual process theories?

There are some. But these are not our main concern.

‘Smith and DeCoster’s (2000) conceptual integration of various domain-specific theories within a single dual-process framework. The central argument of their integrative account is that the multiple dualisms proposed by domain-specific theories reflect the operation of two basic processes that characterize any kind of human thought irrespective of its content: associative versus rule-based processes (cf. Sloman, 1996)’ (Gawronski et al., 2014, p. 7)

the questions

In which domains is there substantial evidence for a two systems theory?

Two Systems Theory of X (core part)

Two (or more) processes concerning X are distinct:
the conditions which influence whether they occur,
and which outputs they generate,
do not completely overlap.

One process makes fewer demands on scarce cognitive resources than the other.

(Terminology: fast vs slow)

notes on our web page

http://two-systems.sinigaglia.and.butterfill.com/

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The Core Idea

The Core Idea

s.butterfill@warwick.ac.uk & c.sinigaglia

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