agents and causes : reconciling competing theories of causal reasoning michael r. waldmann
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Agents and Causes : Reconciling Competing Theories of Causal Reasoning Michael R. Waldmann Cognitive and Decision Sciences Department of Psychology University of Göttingen. With: Ralf Mayrhofer. Overview. Causal Reasoning : Two Frameworks - PowerPoint PPT PresentationTRANSCRIPT
Agents and Causes: Reconciling Competing Theories of Causal
Reasoning
Michael R. Waldmann Cognitive and Decision Sciences
Department of Psychology University of Göttingen
With: Ralf Mayrhofer
1. Causal Reasoning: Two Frameworks• Causal Bayes Nets as Psychological Models
• Overview of empirical evidence• Markov violations in causal reasoning
• Dispositional Theories• Force dynamics• Agents and patients
2. How Dispositional Intuitions Guide the Structuring of Causal Bayes Nets
• Experiments: Markov Violation• Error attribution in an extended causal Bayes net
Overview
Causal Reasoning: Two Frameworks
Causal Models: Psychological Evidence
• People are sensitive to the directionality of the causal arrow (Waldmann & Holyoak, 1992; Waldmann, 2000, 2001)
• People estimate causal power based on covariation information, and control for co-factors (Waldmann & Hagmayer, 2001)
• Causal Bayes nets as models of causal learning (Waldmann & Martignon, 1998)
• People (and rats) differentiate between observational and interventional predictions (Waldmann & Hagmayer, 2005; Blaisdell, Sawa, Leising, & Waldmann, 2006)
• Counterfactual causal reasoning (Meder, Hagmayer, & Waldmann, 2008, 2009)
• Categories and concepts: The neglected direction (Waldmann & Hagmayer, 2006)
• A computational Bayesian model of diagnostic reasoning (Meder, Mayrhofer, & Waldmann, 2009)
• Abstract knowledge about mechanisms influences the parameterization of causal models (Waldmann, 2007)
„The Bayesian Probabilistic Causal Networks framework has stimulated a productive research program on human inferences on causal networks. Such inferences have clear analogues in everyday judgments about social attributions, medical diagnosis and treatment, legal reasoning, and in many other domains involving causal cognition. So far,research suggests two persistent deviations from the normative model. People‘s inferences about one event are often inappropiately influenced by other events that are normatively irrelevant; they are unconditionally independent or are „screened off“ by intervening nodes. At the same time, people‘s inferences tend to be weaker than are warranted by the normative framework.“
Rottman, B., & Hastie, R. (2013). Reasoning about causal relationships: Inferences on causal networks. Psychological Bulletin.
Causal Bayes Net Research: Summary
Markov Violations in Causal Reasoning
The Causal Markov Condition
Definition: Conditional upon its parents (“direct causes”) each variable X is independent of all other variables that are not causal descendants of X (i.e., a cause “screens off” each of its effects from the rest of the network)
E1
E2
E3
C
6
But recent research shows…
• Recent research shows that human reasoners do consider the states of other effects of a target effect’s cause when inferring from the cause to a single effect(see Rehder & Burnett, 2005; Walsh & Sloman, 2007)
vs.
0
0
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1
1
1
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An Augmented Causal Bayes Net?
Rehder & Burnett, 2005
The Causal Markov Condition: Psychological Evidence
• Subjects typically translate causal model instructions into representation that on the surface violate the Markov condition.
• Humans seem to add assumptions about hidden mechanisms that lead to violations of screening-off, even when the cover stories are abstract.
• It is unclear where the assumptions about hidden structure come from. People typically have only sparse knowledge about mechanisms (Rozenblit & Keil, 2002).
Dispositional Theories
Abstract Dispositions, Force Dynamics, and the Distinction between Agents
and Patients• Causation as the product of an interaction between causal
participants (agents, patients) which are endowed with dispositions, powers, or capacities.– e.g., Aspirin has the capacity to relieve headaches. Brains have the
capacity to be influenced by Aspirin.
• Agents (who don‘t have to be humans) are the active entities emitting forces. Patients are the entities acted upon by the agents. Patients more or less resist the influence of the agents.
• Intuitions about abstract properties of agents and patients may guide causal reasoning in the absence of further mechanism knowledge.
Patient
tendencyfor endstate
Affector (i.e., agent)-
patientconcordance
Endstateapproached
Cause No No YesAllow
(enable) Yes Yes Yes
Prevent Yes No No
Wolff’s Theory of Force Dynamics(Wolff, 2007)
Examples„Winds caused the boat to heel“ (cause)„Vitamin B allowed the body to digest“ (allow)„Winds prevented the boat from reaching the harbor“ (prevent)
• Where does the knowledge about tendencies come from if covariation information is excluded?
• How can predictive and diagnostic inferences within complex causal models be explained?
• How do we know whether a causal participant plays the role of an agent or patient?
Problems
How Dispositional Intuitions Guide the Structuring of Causal Bayes Nets
EE.g.,
Hypotheses
1. Both agents and patients are represented as capacity placeholders for hidden internal mechanisms.
2. There is a tendency to blame the agent to a large extent for both successful and unsuccessful causal transmissions.
3. These intuitions can be represented by elaborating or re-parameterizing the causal Bayes net.
Experiments: Markov Violation
An Unfamiliar Domain:Mind Reading Aliens
(see also Steyvers et al., 2003)
POR
PORPOR POR=food(in alien language)
EE.g.,
Dissociating Causes and Agents
I. Cause Effect
Agent Patient
Cause Effect
Patient Agent
II.
Manipulating the Agent Role
1. Sender Condition (Cause Object as Agent)
„Gonz is capable of sending out his thoughts,and hence transmit them into the heads of Murks, Brrrx, and Zoohng.“
2. Reader Condition (Effect Objects as Agents)
„Murks, Brrrx, and Zoohng are capable of reading the thoughts of Gonz. “
Gonz
Murks
Brrrx
Zoohng
Experiment 1a: Which Alien is the Cause?(Intervention Question)
Cause Effect0
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ReadingSending
Pro
babi
lity
of "P
OR
"
Imagine „POR“ was implantedin head of cause/effect alien. How probable is it that the other alien thinks of „POR“.
Experiment 1b: Blame Attributions
Who is more responsible,if cause is present andeffect absent, the cause alienor the effect alien?
Reading Sending0
10
20
30
40
50
60
70
80
90
100
CauseEffect
Bla
me
Attr
ibut
ions
(in
%)
?
Markov Violations: Experiment 2
Instruction: 4 aliens either think of POR or not; thoughts of pink top alien (cause) covary with thoughts of bottom aliens (effects); aliens think of POR in 70% of their time.
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Test Question: “Imagine 10 situations with this configuration. In how many instances does the right alien think of POR?”
Predictions
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Sender Condition: The pattern seems to indicate that something is wrong with Gonz‘s capacity to send. Hence, the probability of Murks having Gonz‘s thought should be low (i.e., strong Markov violation).
Reader Condition: The pattern seems to indicate that something is wrong with Brrrx‘s and Zoohng‘s capacity to read. Hence, the probability of Murks having Gonz‘s thought should be relatively intact (i.e., weak Markov violation).
Gonz
Murks
F=0 F=1 F=20
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Sender
Reader
Results: Experiment 2?
Error attribution in an extended causal Bayes net
Stan
Error attribution in causal Bayes nets
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EC wC
Standard Model:
Distinguishing between two types of error sources
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EC
FC
wC
C
FC
E
FE
Differentiating between Cause (FC)- and Effect (FE)-Based Preventers:
Simplified Version:
Error Attribution in a Common Cause-Model
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E2
C
En
FC
E1…
wC
• FC is an unobserved common preventer, and must be
inferred from the states of C and its effects• When C involves the agent, the strength of FC is high (i.e.,
error is mainly attributed to C), when E involves the agent, the strength of FC is low (hence errors are primarily
attributed to the individual effects (i.e., FE, that is, wC).
Model Predictions
C
E1
E2
E3
FC
0 1 2
020
4060
8010
0
# of observed effect features being on
infe
renc
e ra
ting
CC=0CC=1
beta(1,1)beta(5,1)beta(100,1)
The strength of the FC (red
– green – blue) influences the size of the Markov violation (i.e., slope).
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wF_C
Further Predictions (1): A/B Case
• In the basic experiments an asymmetry between the two states of the cause was found
• In the absent case the cause is not active, thus mechanism assumptions cannot have an influence
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• Prediction: When both states of the cause are described as active, the differential assumptions about error attribution should matter in both cases
NE0 NE1 NE20
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Sending
Reading
Markov-Experiment A/B: Results?
N=5619
Further Predictions (2): Causal Chains
• If each C comes with its own FC, the
difference between reading and sending conditions should completely disappear in a causal chain situation
IC1 DCIC2 EFC FC FC
20
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0/2 1/1 2/00
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Sending
Reading
Chain Experiment: Results?
N=5021
• Causal model instructions are typically augmented with hidden structure.
• In the absence of specific mechanism knowledge intuitions about abstract dispositional properties of causal participants guide the structuring of the models.
Summary