Physical Self-Concept in Adolescent Girls: Behavioral and Physiological Correlates

Article excerpt

Key words: body fat, cardiovascular fitness, physical activity, self-esteem

For the past two decades, researchers in exercise and sport psychology have worked to refine an instrument to measure the subjective evaluations of the physical self. These perceptions of physical competence and appearance, known as physical self-concept, are believed to contribute to global self-esteem in a hierarchical fashion (Shavelson, Hubner, & Stanton, 1976). According to this model, perceptions of one's behavior in particular situations influence appraisals of the self in certain domains (e.g., physical, academic, and social), which combine to create an overall self-concept. Although it was historically assessed as a single construct, emphasis on the hierarchical nature of physical self-concept has given way to multidimensional measures. Recently, instruments with the ability to distinguish between specific components of physical perceptions (e.g., health, fitness, and body composition) have been developed (Fox, 1990; Marsh, Richards, Johnson, Roche, & Tremayne, 1994; Richards, 1988).

Among these multidimensional measures, the Physical Self-Description Questionnaire (PSDQ) has demonstrated superior psychometric properties. In a multitrait-miltimethod analysis of an adolescent Australian sample, Marsh et al. (1994) found the PSDQ to have higher internal reliability and factor loadings than comparison instruments. Confirmatory factor analyses differentiating the 11 scales of the PSDQ and demonstrating good test reliability have also been provided (Marsh, 1996b). Nigg, Norman, Rossi, and Benisovich (2001) recently replicated these unique factor loadings of the PSDQ scales in an American university sample. Despite sound support for the internal structure of the PSDQ, less evidence for its construct validity has been provided.

Research attempting to validate the PSDQ using external criteria has been limited. In one study, Marsh (1996b) found that the PSDQ endurance and sports competence scales were most highly correlated with field tests of cardiovascular endurance. Scores on the PSDQ scales were also associated with corresponding behavioral measures of physical activity, endurance, strength, body composition, and flexibility (Marsh, 1996a). These results generally supported the convergent and discriminant validity of the PSDQ scales. Consistent with the hierarchical framework proposed by Shavelson et al. (1976), Marsh's (1996a) findings also suggested that objective measures of physical abilities and composition might be more closely related to specific (e.g., perceived endurance and body fat) versus global aspects of self-esteem.

The current research study sought to further contribute to the PSDQ construct validation literature by (a) using more sensitive measures of physiological and behavioral criteria than have been used in the past and (b) determining whether the PSDQ is valid for use in a relatively unfit population. Previous validation studies relied on external criteria gathered in field settings (e.g., shuttle run, 50-m dash, body mass index, skinfolds, and body girth; Marsh, 1996a, 1996b). The present study objectively assessed body composition and cardiovascular fitness field through clinically based instruments (e.g., dual x-ray absorptiometer and ramp-type progressive exercise test). In addition, past research has tested the PSDQ in samples representing an average to high range of cardiovascular fitness (Marsh, 1996a, 1996b; Marsh, Hey, Roche, & Perry, 1997; Marsh et al., 1994; Nigg et al., 2001). Information about the validity of PSDQ assessments in unfit populations is lacking. The present study determined if PSDQ physical perceptions accurately reflect behavioral and physiological parameters in a sample of low-active adolescent girls.

The study tested the hypotheses that physiological and behavioral measures would correlate strongly with specific PSDQ scales assessing corresponding perceptions and weakly with the PSDQ global self-esteem scale. …