posted on 2010-11-19, 12:01authored byMartin S. Hagger
A series of studies aimed to examine the role of perceived behavioural control in
Ajzen's (1985) Theory of Planned Behaviour (TPB) in a physical activity context
with children aged 12-14 years. A broader, more differentiated role of perceived
control was envisaged in the theory based on the conceptualisation of control and
perceived competence put forward by Skinner (1995). The first two studies examined
the role of control with respect to the TPB model variables and past behaviour. Study
1 investigated the relations between intention, behaviour, attitude, subjective norms
and perceived behavioural control in 181 children. It was hypothesised that attitude,
perceived control and subjective norms would be related to intention and intention to
behaviour. In addition, it was hypothesised that the covariation between control and
attitude observed in previous studies could be better explained by the specification of
a direct path between perceived control and attitude. Path analysis confirmed the
theoretical relations between the TPB variables and, uniquely, the existence of a
perceived control- attitude path forming a triadic arrangement with attitude and
intention. It was concluded that perceived control governed two routes to the
formation of intentions: a direct, spontaneousp ath and an indirect, more deliberative
path via attitudes. This relationship was subsequently confirmed in a sample of 382
children in Study 2 using latent measures of attitude and control. The study
demonstrated that direct attitude-intention and attitude-behaviour paths regulated the
intention-behaviour relationship and attenuated the control -intention relationship to
zero. Further, past behaviour predicted control but not intentions or prospective
behaviour suggesting that perceived control includes judgements regarding previous
control experiences. Since Studies I and 2 indicated the diverse influence of control
on the TPB variables, Study 3 diversified the perceived control variable according to
Skinner's (1995) conceptualisation of control. This was achieved through the
inclusion of a measure of self-efficacy alongside perceived control in a study of 1152
children. The resulting non-standard model using both latent and observed measures,
indicated that self-efficacy regulated the control-intention relationship, while control
remained an indirect predictor of intention via attitudes. It was concluded that the
spontaneous pathway was largely due to the aspects of control related to past
experiences of confidence or self-efficacy. This justified the diversification of the
perceived control variable and indicated that when young people consider the control
they have over certain behaviours, they refer to a number of different perceptions. To
further examine the role of perceived control and examine the origins of the cognitive
variables in the TPB, Study 4 examined perceived control from a human needs
perspective in 1088 children. The measures included more general, domain-specific rather than behaviour- specific measures of perceived control and locus of causality
(PLOC). The latter variables represented the human needs for competence and
autonomy, which are hypothesised to be motivational in nature (Deci & Ryan, 1985).
Results indicated that relative autonomy predicted perceived behavioural control and
attenuated the control-intention relationship to zero. This suggested that autonomy
was the driving force behind the process of intern ali sation, in which a person
assimilates a behaviour by continual competence satisfying experiences. A final study
aimed to confirm the triadic relationships between attitude, perceived control and
intention in the TPB by a cumulative analysis of these relationships using the data
from Studies 1-4. Meta-analytical techniques were used to produce cumulative
correlations corrected for measurement and sampling error between the TPB
relationships. Results indicated that the variation in the correlations may have been
due to more than just sampling error, indicating the existence of moderating variables.
A path analysis using these correlations indicated that the atti tude- intention
relationship in the triadic arrangement tended to be attenuated by the control-intention
relationship. This series of studies indicate that Perceived behavioural control is an
important and diverse predictor of intention in the TPB. In particular, control was
shown to be an antecedent of attitudes as well as a direct predictor of intentions and
that spontaneous intention formation from control perceptions may have been due to
self-efficacy beliefs and past behavioural beliefs being encompassed by perceived
control. Finally, the adoption of self-determination theory indicated that more general
motives for engaging in physical activity behaviour were antecedent variables of
control, attitudes and intention from a social cognitive approach. Such theories helped
interpret the relationships in the TPB, in particular the role of control as an important
variable in the process of internalisation.