Self-identity as a component of the Theory of Planned Behaviour in predicting physical activity

Abstract

This study aimed to investigate the role of self-identity, defined as salient and enduring aspects of one’s self-perception (Sparks, 2000), in relation to adolescent physical activity (PA) intentions within the Theory of Planned Behaviour (TPB). School students aged 12 to 18 from two cultural groups (Estonia and Spain) completed measures of attitudes, subjective norms, perceived behavioural control, self-identity, and intentions for PA. Four weeks later participants completed self-reported measures of PA. A structural equation model showed that self-identity had a direct effect on PA intention (β = .33, p < .01) and PA behaviour (β = .31, p < .01). The model accounted for 45% of the variance of PA behaviour from which 4% can be attributed to self-identity. The effect of self-identity on PA was also partially mediated via intention. The multi-group comparison between two cultural groups indicated that no invariances existed between the models of the observed samples.

The effect of self‐identity alongside perceived importance within the theory of planned behaviour

“…That self‐identity predicted intentions after TPB components were accounted for is consistent with much previous research (e.g., Booth et al., ; Nigbur et al., ; Ries et al., ). However, that this effect was found even though we included a measure of perceived importance serves to extend previous research.…”

“…Self-identity predicts intentions after standard TPB components have been accounted for in a range of behavioural contexts, including physical activity (Jackson, Smith, & Conner, 2003;Ries, Hein, Pihu, & Armenta, 2012), alcohol consumption (Conner, Warren, Close, & Sparks, 1999), sexual health (Booth, Norman, Harris, & Goyder, 2014), environmental activism (Fielding, McDonald, & Louis, 2008), and recycling (Mannetti, Pierro, & Livi, 2004;Nigbur, Lyons, & Uzzell, 2010;Terry et al, 1999). Further, a meta-analysis of 40 studies found that self-identity enhanced the prediction of intentions beyond TPB components, accounting for 6% of additional variance in intentions (Rise et al, 2010).…”

An extended version of the theory of planned behaviour: the role of self-efficacy and past behaviour in predicting the physical activity of Chinese adolescents

“…According to Ajzen (1991), the TPB is open to further expansion as long as a strong theoretical justification for the inclusion of additional predictors is provided. Consequently, several recent studies have added variables in the TPB, such as self-identity (Ries, Hein, Pihu, & Armenta, 2012), past behaviour (Norman, Conner, & Bell, 2000), group norms, family social support, friends, social support and social provisions (Hamilton & White, 2008), past behaviour and anticipated negative emotions (Wang, 2011) and self-efficacy and past behaviour (Hagger, Chatzisarantis, Biddle & Orbell., 2001), to predict adolescent physical activity intention and behaviour. These variables have accounted for some of the additional variance in behavioural intentions or behaviours over the TPB constructs.…”

<p>Predicting Stage of Exercise Among Patients with Type 2 Diabetes: A Test of the Extended Theory of Planned Behavior</p>

“…Recently, two variablesself-identity and descriptive normhave been discussed for inclusion as additional predictors of exercise intention and behavior within the TPB. 4,5 Subjective norm has been identified as the individual's perception about what significant others think ought to be done. 6 Recently, Ajzen and Fishbein stated that the subjective norm construct should also include the individual's perception about what significant others do (descriptive norm).…”

“…13 A meta-analysis found that self-identity could exert a direct influence on behavior itself in the exercise domain. 5 Despite the research supporting the influence of self-identity on behavioral intention, there is no research exploring the role of self-identity within the TPB in relation to exercise in Chinese patients with type 2 diabetes.…”