Week 7 Systems Theories

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• Goodson Chapter 7
• Resnicow & Page, 2008
• Krieger, 1994
Pattern 3: Deliberate Privileging of
Linearity: The Whole or the Sum of
the Parts?
Goodson, P. (2010). Theory in Health Promotion
Research and Practice. Mississauga, Ontario:
Jones and Bartlett Publishers.
Limitations of Linear Theories
• Focus on the individual
• Focus on cognitive factors
• “the whole is equal to the sum of its parts”
“this orderly, linear framework remains the mainstream
foundation of the human and social sciences to this day.”
(Cooper & Geyer, 2008)
Complexity Theories
• Offer a non-linear way to explain
unpredictability, complexity, and dynamic
aspects of behavior
• “Complex Adaptive Systems (CASs) consist of a
set of interacting elements that are able to
change and adapt in multiple ways
(Zimmerman, Lindberg, & Plsek, 1998).”
Complexity Theories
1. Whole is more than
the sum of its parts
2. CASs comprise other
CASs
3. Agents within CASs
evolve
4. Sustainability depends
on diversity
5. Decentralized, or
“distributed” control
6. Size of output does not
necessarily correspond
to size of input
7. Dependence on original
conditions (“Butterfly
Effect”)
8. CASs drawn to attractors
9. Unpredictable behavior
10. Order to the chaos
What are Attractors?
Examples
• School district
• Puzzle
• Others?
Challenges in practice:
Allowing a system to self-organize?
Recognizing how behavior itself influences the
system?
Goodson Chapter 7
• Empirical evidence
• Statistical implications
• Cautions
Embracing Chaos and Complexity: A
Quantum Change for Public Health
Resnicow, K. and Page, S.E. (2008). American
Journal of Public Health, Vol 98, No. 8, pp. 13821389.
Resnicow & Page, 2008
• Propose that the linear paradigm is
flawed
• Key Principles:
–Quantum behavior change
–Chaotic process, sensitive to initial
conditions
–Occurs within CASs
Quantum Change
•
•
•
•
Wave/particle
Dramatic experience OR
Sudden insight (Miller)
Can occur with little input
Initial Conditions
•
•
•
•
Butterfly Effect
Infinite permutations
Fractal patterns
Identification of fractals suggests
intervention points
Change as a CAS
• “particle components of a
motivational quantum” = different
starting points
• Multiple pathways
• “lever points” or “tipping points”
Implications for Public Health
• Identification of leverage points
• Consideration of timing and initial
conditions
• View behavior as probabilistic
• Encourage “wing flapping”?
Resnicow & Page, 2008
• Empirical evidence
• Statistical implications
Unify Linear and Complex?
Resnicow & Page, 2008
• Practical implications
–Repeated exposures
–Understand individual “receptivity”
(sounds familiar)
–Lower upper limit on variance
explained
Resnicow & Page, 2008
• Potential areas of research
–Qualitative methods
–Quantitative methods
–Physiological mechanism studies
–Agent-based and computational
modeling
Epidemiology and the web of
causation: Has anyone seen the
spider?
Krieger, N. (1994). Soc. Sci. Med.
Vol. 39, No. 7, pp. 887-903
Epidemiologic Theory
• Web of Causation and multivariate analyses
• “paucity of critical reflection”
• Insufficient preparation of new
epidemiologists
Web of Causation
MacMahon, Pugh, Ibsen (1960) as a challenge to “chain of causation”
Web of Causation
• Increased understanding of interaction and
confounding
• Rothman
Problems with Web
•
•
•
•
Omitted discussion of origins
Lacks discussion of theory for the model
Focus on proximal factors
Does not distinguish between individuals and
populations
• “biomedical individualism”
Modern Contributions
•
•
•
•
•
“environment” ill-defined (Vanderbroucke)
Resurgence of single agent theory
McKeown’s etiologic groups
Social determinants
Conclusion: Epi still lacking an ecosocial
theory
Ecosocial Framework
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•
•
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How to use epidemiological data
Greater precision in etiology
Better definitions of “lifestyle”
Challenge to current definition of
“environment”
• Challenge to rigid distinctions of individual
and group level analyses
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