Download - L2. Causal Modelling
-
8/14/2019 L2. Causal Modelling
1/31
Causal Modelling
Reading: Ch 1-3 of Morton, J. (2004)
Understanding Developmental Disorders: ACausal Modelling Approach. Blackwell
Publishing
(Copies available on closed reserve)
-
8/14/2019 L2. Causal Modelling
2/31
-
8/14/2019 L2. Causal Modelling
3/31
Development
Unfolding of a particular pattern, as a result ofvariation in genes and variation in the
environment
Waddington (1940); reproduced in Slack (2002)
-
8/14/2019 L2. Causal Modelling
4/31
Development
Waddington (1940); reproduced in Slack (2002)
-
8/14/2019 L2. Causal Modelling
5/31
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)
-
8/14/2019 L2. Causal Modelling
6/31
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
-
8/14/2019 L2. Causal Modelling
7/31
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)
-
8/14/2019 L2. Causal Modelling
8/31
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
-
8/14/2019 L2. Causal Modelling
9/31
Theories
Evaluating theories
Falsifiable
Empirically sound
Internally consistent
It should be parsimonious
It should integrate previous research
-
8/14/2019 L2. Causal Modelling
10/31
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?
-
8/14/2019 L2. Causal Modelling
11/31
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
-
8/14/2019 L2. Causal Modelling
12/31
Other plausible models
Workingmother
Low achievement
child
Childsstate
of mind
Workingmother
Childsstate
of mind
Low achievementchild
-
8/14/2019 L2. Causal Modelling
13/31
Plausible models become complex
Workingmother Childs
stateof mind
Motherunavailable
Workingmother
Motherunavailable
No talkof
school
Child nointerestin school
Low achievementchild
Low achievementchild
-
8/14/2019 L2. Causal Modelling
14/31
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?)
-
8/14/2019 L2. Causal Modelling
15/31
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
-
8/14/2019 L2. Causal Modelling
16/31
Causal Modelling
Biology
Cognition
Behaviour
-
8/14/2019 L2. Causal Modelling
17/31
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
-
8/14/2019 L2. Causal Modelling
18/31
Causal Modelling
Key points
Distinguishes between various levels of
discourse
biology, cognition, behaviour
Allows both genetic and environmental factors
Distinguishes between descriptive modelsand causalmodels
-
8/14/2019 L2. Causal Modelling
19/31
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
-
8/14/2019 L2. Causal Modelling
20/312
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
-
8/14/2019 L2. Causal Modelling
21/312
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
-
8/14/2019 L2. Causal Modelling
22/312
Autism
biological
cognitive
behavioural
TwinsMore boys than girls
Theory of mind/EFNo imagination
Good drawingSocially strangeLow IQ
-
8/14/2019 L2. Causal Modelling
23/312
Autism
biological
cognitive
behavioural
TwinsMore boys than girls
Theory of mind/EFNo imagination
Good drawingSocially strangeLow IQ
virus?
faultyattachment?
-
8/14/2019 L2. Causal Modelling
24/312
Autism
genetic factor
brain
abnormality
-
8/14/2019 L2. Causal Modelling
25/312
Autism
genetic factor
brain
abnormalityvirus
-
8/14/2019 L2. Causal Modelling
26/31
-
8/14/2019 L2. Causal Modelling
27/312
Autism
cognitive
cause
lack of
imagination
lack of
ToM
-
8/14/2019 L2. Causal Modelling
28/312
Autism
cognitive
cause
lack of
imagination
lack of
ToM
socially
strange
behaviour
-
8/14/2019 L2. Causal Modelling
29/312
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
-
8/14/2019 L2. Causal Modelling
30/313
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
-
8/14/2019 L2. Causal Modelling
31/31
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