Transcript Theory of Planned Behaviour and Physical Activity

Theory of Planned Behaviour
and Physical Activity
EPHE 348
Origins
• Attitudes were a major focus in psychology
during the 1930s
• Evidence was often not supportive of
attitude-behaviour relations
Problems with earlier research
• Aggregate assessment
• Specificity (action, context, time-frame,
target)
Theory of Reasoned Action
• Fishbein & Ajzen (1975) postulated a
theoretical model for understanding
behaviour centered around the attitude
construct
• Remains the most influential attitude
model 30 years later
TRA
• Attitudes – overall evaluation of a
behaviour
• Subjective norm – overall perceived
expectation to perform the behaviour from
others
• Intention – summary motivation to enact
the behavior
TRA Principles
• Attitude and subjective norm influence
behaviour through intention
• Importance of attitude and subjective norm
can differ by behavior or target group
But what makes up an attitude?
• Attitudes are a function of underlying
beliefs about the behavior
– Weighted Expectancy x Value
• Norms are a function of normative beliefs
(norm x value of referent)
Theory of Planned Behaviour
• Due to the popularity and demonstrated
importance of self-efficacy, the TRA was
extended to include a control construct
• Perceived behavioural control – ability of
the individual to carry out the behaviour
(skills, opportunity, resources)
Perceived Behavioural Control
• Also an E x V construct:
– Belief of capability to overcome an obstacle x
the probability that the obstacle will occur
• Ajzen (1991) argues that PBC influences
intention and, to the extent that it
represents real control, behaviour directly
Theory of Planned Behavior (Ajzen, 1985)
Attitude
Subjective Norm
Intention
Behavior
Perceived
behavioral control
Figure 14.1
What causes the beliefs?
• Ajzen and Fishbein leave this open but
include personal and observational
experience, personality, demographics,
environment, culture among others…
TPB and PA
• Over 100 studies with various populations
• Intention related to PA large effect size
• Attitude and PBC are related to PA with a
medium to large effect size and related to
intention with a large effect size
• Subjective norm related to behaviour and
intention with a small effect size
PA Beliefs
• Most important behavioural beliefs:
– Stress relief, takes too much time, fun thing to do
• Most important behavioural value:
– Health, physical appearance/weight control
• Most important normative beliefs and values:
– friends, family, spouse/romantic partner
• Most important control beliefs and values
– Time
– Fatigue
Multi-Component TPB
• Attitude, subjective norm, and PBC are multi-faceted:
– Attitude = affect, instrumental
– Subjective norm = injunctive, descriptive
– PBC = skills, opportunity, resources
•
•
Rhodes, R.E., Blanchard, C.M. & Matheson, D.H. (2006). A multicomponent model of the theory of planned behaviour. British Journal of
Health Psychology, 11, 119-137.
Rhodes, R.E. & Courneya, K.S. (2003). Investigating multiple components
of attitude, subjective norm, and perceived control: An examination of the
theory of planned behavior in the exercise domain. British Journal of Social
Psychology, 42, 129-146.
Intention behavior relations
• Intention-behavior asymmetry is from intenders
not acting and not from nonintenders acting
• The more one intends to exercise, the more
likely one is to fail at achieving one’s intentions
(>3 becomes very problematic)
• Rhodes, R.E., Courneya, K.S. & Jones, L.W. (2003).
Translating exercise intentions into behaviour:
Personality and social cognitive correlates. Journal of
Health Psychology, 8, 449-460.
Temporal Profiles of Exercise Behavior Motivation
ACTION PLANNING
ACTION CONTROL
AFFECTIVE EVALUATIONS
INSTRUMENTAL EVALUATIONS
NonIntenders
Unsuccessful
Intenders
SOCIAL NORMATIVE EVALUATIONS
CONTROL EVALUATIONS
Successful
Intenders
TPB in intervention
• Few studies have focused on TPB-based
intervention
• Basic premise is that behaviour can be
changed three ways:
– Increase or decrease a belief
– Create a belief
– Increase or decrease a value
Belief Tests
• Chatzisarantis & Hagger (2005)
• Study of Adolescents and modal vs non
beliefs showed differences in intention via
attitude
Properties of Physical Activity
Attitude
Boring
Affective
Unpleasant
Physical
Activity
Instrumental
Attitude Tests
• Conner & Rhodes (2008)
• Undergraduate samples given either
completely affective message or
completely instrumental message
• Examined effect on attitudes, intention,
and behaviour (2 weeks later)
Effect on Behaviour
8
7
6
5
Control
4
Affective
3
Cognitive
2
1
0
Time 1
Time 2
Attitude Tests
• Parrott et al. (2008)
• Persuasive Messages sent to
Undergraduates (3 week follow-up)
• Focused on Instrumental followed by
Affective Attitude compared to no
message
• RESULTS – Dependent on baseline
status.
Making an Enemy an Ally
• Can the reinforcing and distracting
properties of video games be used to
facilitate exercise?
UVIC/UBC Gamebike Study
• 27 sedentary young men randomly assigned to
a stationary bike or video game bike
• Advised to attend 30 min sessions 3xweek
• 6 weeks
• Measured on fitness and psychological variables
Physiological Effects
(Warburton et al., 2007)
Maximal Aerobic Power (mL.kg-1.min-1)
60
**
50
PRE
POST
40
30
20
0
TRADITIONAL
VIDEO
Experimental Condition
Fitness results were better in the video game condition
Why? Attendance
3.5
Traditional
Video
Weekly Attendance
3.0
*
2.5
2.0
1.5
1.0
0.5
0.0
0
1
2
3
Training Week
4
5
6
Gamebike
Attendance
Fitness
What is going on with Attendance?
• Participants report lower exertion in the
videobike condition than controls despite
higher power output (Sarkany et al., 2006)
• Participants report greater affective
attitude (i.e., enjoyment) in the videobike
condition (Rhodes et al., in press)
6
*
*
Affective Attitude
5
4
Videobike
3
Standard Bike
2
1
0
Time 1
Time 2
Mechanism
Gamebike
Affective
Attitude
Attendance
Fitness