L2. Causal Modelling

8/14/2019 L2. Causal Modelling

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Causal Modelling

Reading: Ch 1-3 of Morton, J. (2004)

Understanding Developmental Disorders: ACausal Modelling Approach. Blackwell

Publishing

(Copies available on closed reserve)


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Development

Unfolding of a particular pattern, as a result ofvariation in genes and variation in the

environment

Waddington (1940); reproduced in Slack (2002)


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Development

Waddington (1940); reproduced in Slack (2002)


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Developmental theories

Child psychology today is surprisingly free of

interest in building models of general

development. The discipline is filled with

hyperactive attempts to accumulate data, but

attempts to make sense of the data, in terms of

models of basic developmental processes, arerelatively rare. (Valsiner, 1998, p.189)


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Theories

Theories map explanatory concepts onto

observations of phenomena to be explained

through the use of bridging principles

Development of STM capacity

STM capacity increases during childhood

rehearsal rate, phonological store

memory span depends on rehearsal rate

rehearsal rate increases with age


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Theories

Theories tell us how to select, organize and

interpret observations. They provide economical

summaries of observations.

Science is built up of facts, as a house is built

of stones; but accumulation of facts is no

more science than a heap of stones is ahouse.(Jules Henri Poincare, 1952)


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Theories

Theories provide explanations of behaviour, and

explanations are necessary if we wish to predict

the behaviour of different individuals in different

contexts at different times

Guide research

empirical statements must be tested

stimulate new observations


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Theories

Evaluating theories

Falsifiable

Empirically sound

Internally consistent

It should be parsimonious

It should integrate previous research


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Developmental Theories

Issues specific to developmental theories

What is it that develops?

How do nature and nurture contribute to

development?

Is the basis of developmental change

qualitative or quantitative?


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Headline: Working mums blamed for

childrens failures

Full time workingmother

Low achievementchild

Even if this could be established as a causal

relation, intervention requires understanding the

mechanisms


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Other plausible models

Workingmother

Low achievement

child

Childsstate

of mind

Workingmother

Childsstate

of mind



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Plausible models become complex

Workingmother Childs

stateof mind

Motherunavailable

Workingmother

Motherunavailable

No talkof

school

Child nointerestin school




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Causal Modelling

Establishing cause is a complex issue

Vast number of factors that may contribute to

the effect

Must define the problem properly

Need a framework within which underlying

ideas about cause can be expressed

Must distinguish causal relationships from

contingent ones (i.e. does being male cause

delinquency?)


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Causal Modelling

Morton & Frith (1995)

Developed a framework within which causal

models could be expressed

The framework is theory neutral

Allows the comparison of alternative theories

about developmental psychology

Causal modelling is a tool


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Causal Modelling

Biology

Cognition

Behaviour


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Causal Modelling

The jump between gene and behaviour is too big

identifying genetic basis doesnt really explain

behaviour (almost everything is heritable)

probability of outcome given the gene is low

Cognition is an essential part of any theory of

development

Cognitive factors mediate between biology and

behaviour


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Causal Modelling

Key points

Distinguishes between various levels of

discourse

biology, cognition, behaviour

Allows both genetic and environmental factors

Distinguishes between descriptive modelsand causalmodels


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Ground Rules of Causal

Modelling

1. Start with biology

2. Build causal chains

3. Give a full account

4. Specific over general

5. Distinguish cognitive from behaviour


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Ground Rules of Causal

Modelling

6. Be cognitively economical

7. Correlation is not causation

8. Avoid circularity

9. There is no single cause of anything

10. Nothing is determined


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Autism

Some have outstanding drawing/memory

Lower IQ

Slow to learn language

Theory of mind or executive deficit?

Socially strange

No imagination

Good at hidden figures/proof reading Genetic link (i.e. co-occurence in twins)

Occurs more in boys than girls

Early onset


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Autism

biological

cognitive

behavioural

TwinsMore boys than girls

Theory of mind/EFNo imagination

Good drawingSocially strangeLow IQ


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Autism

biological

cognitive

behavioural

TwinsMore boys than girls

Theory of mind/EFNo imagination

Good drawingSocially strangeLow IQ

virus?

faultyattachment?


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Autism

genetic factor

brain

abnormality


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Autism

genetic factor

brain

abnormalityvirus


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Autism

cognitive

cause

lack of

imagination

lack of

ToM


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Autism

cognitive

cause

lack of

imagination

lack of

ToM

socially

strange

behaviour


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Autism

geneticdifference

brain

difference

brain

difference

ToM

deficit

lack of

imagination

low general

ability

social convention

not learned

function of

language

not learned

socially strange

behaviour

delay in

language

no pretend

play

low

IQ

biological

cognitive

behavioural


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Causal Modelling

Representing causal relationships

help sort out thoughts, distinguish facts and

theories

separate biological, cognitive and

behavioural elements

a productive way of viewing and comparing

theories


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Summary

Developmental theories

necessary to organise facts & generate

predictions

characteristics of a developmental theory

Nature of cause

Causal modelling approach

biology, cognitive, behavioural

Example: Autism

Documents

L2. Causal Modelling