Health Psychology, 2nd Edition

HEALTH COGNITIONS AND BEHAVIOURS 151

Affective

attitudes

Cognitive

attitudes

Injunctive

norms

Subjective

norm Intention Behaviour

PBC

Actual

behavioural

control

Attitude

Descriptive

norms

Perceived

confidence

Perceived

control

FIGURE 7.4The two-factor theory of planned behaviour.

individuals to have not quit smoking themselves. PBC is divided into perceived control
and perceived confidence. So, for example, one might perceive that quitting smoking
is within one’s control but not feel confident that one can easily quit smoking. The
latter factor is most like self-efficacy and has been found to be the stronger predictor
of intentions and behaviour (Rodgers, Conner and Murray, 2008).

Social cognitive theory

In social cognitive theory (SCT; Bandura, 1982) behaviour is held to be determined
by three factors: goals, outcome expectancies and self-efficacy (see Figure 7.5). Goals
are plans to act and can be conceived of as intentions to perform the behaviour (see
Austin and Vancouver, 1996; Luszczynska and Schwarzer, 2005, 2015). Outcome
expectancies are similar to behavioural beliefs in the TPB but here are split into
physical, social or self-evaluative depending on the nature of the consequences
considered. Thus, in this model, beliefs about others’ approval (subjective norms in
the TPB) are grouped with beliefs about other consequences. Self-efficacy is the belief
that a behaviour is or is not within an individual’s control and is usually assessed as
the degree of confidence the individual has that they could still perform the behaviour
in the face of various obstacles. This is very similar to PBC in the TPB and particularly
the perceived confidence component in the two-factor TPB. Bandura has recently
added socio-structural factors to his theory. These are factors assumed to facilitate
or inhibit the performance of a behaviour and affect behaviour via changing goals.
Socio-structural factors refer to the impediments or opportunities associated with
particular living conditions, health systems, political, economic or environmental
systems. They are assumed to inform goal setting and be influenced by self-efficacy.