MOTL, R. W., and D. E. CONROY. Validity and factorial invariance of the Social Physique Anxiety Scale. Med. Sci. Sports Exerc., Vol. 32, No. 5, pp. 1007–1017, 2000.
Purpose: The present study 1) tested whether the two-factor model to the 12-item Social Physique Anxiety Scale (SPAS) was substantively meaningful or a methodological artifact representing positively and negatively worded items, 2) assessed the factorial validity of the nine-item unidimensional model to the SPAS, 3) examined whether modifying the number of SPAS items would improve the factorial validity, 4) evaluated the factorial invariance of the SPAS across gender, and 5) explored the construct validity of SPAS scores.
Methods: Female (N = 146) and male (N = 166) college students (22.2 ± 4.0 yr) in lecture (N = 103) and physical activity (N = 209) courses completed the SPAS, Physical Self-Efficacy Scale (PSES), Surveillance subscale of the Objectified Body Consciousness Scale (S-OBCS), and short form of the Marlowe-Crowne Social Desirability Scale (SDS-C).
Results: Confirmatory factor analyses (CFA) revealed that the two-factor model to the 12-item SPAS was a methodological artifact representing positively and negatively worded items. CFA indicated that the nine-item unidimensional model represented an acceptable fit to the SPAS, but it also could be improved. Modifications based on standardized residuals and item content led to the removal of two items and a seven-item unidimensional solution to the SPAS. The nine- and seven-item models demonstrated factorial invariance across gender. Correlation analyses between nine- and seven-item SPAS scores to PSES, S-OBCS, and SDS-C provided support for the construct validity.
Conclusions: The nine- and seven-item unidimensional models to the SPAS demonstrated evidence of factorial validity, factorial invariance, and construct validity; the two-factor model to the SPAS represented a methodological artifact.
There has been an increased interest in utilizing self-presentation theory (14,22) to understand behavior in physical activity environments (21). For example, researchers have examined the construct of social physique anxiety in physical activity environments because it may have important implications for understanding exercise and sport behavior. Social physique anxiety has been related to avoidance of public exercise settings, preferences for exercise settings differentially emphasizing one’s physique, and self-reported leisure time physical activity (7,20,37), and it may influence an individual’s willingness to engage in some types of physical activity (21). Social physique anxiety also has been related to self-presentation issues such as physical attractiveness, physical self-presentation confidence, satisfaction with body size and weight, and weight control (7,11,27,29), and it even may detract from the positive affective responses associated with exercise (21).
The majority of research examining the construct of social physique anxiety has employed the Social Physique Anxiety Scale (SPAS)—a 12-item, unidimensional measure of anxiety related to the perceived negative evaluation of one’s physique by others (15). The factorial validity of the SPAS has been scrutinized (12,13,28,29,34), and it is not well established. Researchers initially reported that a one-factor model adequately described responses to the SPAS using exploratory factor analysis (15), and the one-factor model was further supported using confirmatory factor analysis (CFA; 29). Subsequent research tested the fit of three different models (one-factor unidimensional model, two-factor uncorrelated model, and two-factor higher-order model) to the SPAS utilizing CFA. Results indicated that the higher-order model, which consisted of two first-order factors (physique presentation comfort and expectations of negative physical evaluation) subordinate to a second-order factor (social physique anxiety), represented the best fit to the SPAS (13). The two-factor higher-order model was further supported by other research (34), and it has been reported to be invariant across gender (12).
Although the two-factor higher-order model has received empirical support, it also has been questioned as a valid solution to the SPAS (10,13,28). The multidimensional model to the SPAS may be conceptually flawed (10,13,28). The higher-order model was not identified according to the three-indicator rule (4, p. 247), and it was not supported in an analysis of factorial invariance (12); the test of invariant factor structure resulted in a larger chi-square value than the test of invariant variance-covariance matrices. The two factors in the higher-order model even may represent method variance (i.e., error) rather than true score variance, because all positively worded items load on one factor and all negatively worded items load on the other factor. Marsh (26) and Tomás and Oliver (39) have reported a similar phenomenon with a measure of global self-esteem and utilized CFA methodology to test whether two-factor models associated with positively and negatively worded items are substantively meaningful or methodological artifacts.
Rather than testing the fit of various models to the 12-item SPAS, some researchers have opted to modify the number of SPAS items in an attempt to improve the factorial validity (28,29). For example, Martin and colleagues (28) recently provided a nine-item unidimensional solution to the SPAS. The nine-item solution was generated based on conceptual and statistical arguments. Two of the original SPAS items did not appear to possess social evaluation components and correlated strongly with measures of body satisfaction; one of the original items (item 2) has consistently demonstrated a weak factor loading (12,13,29,34). The three items were removed and the remaining nine items were subjected to CFA to test the unidimensional model in four separate samples of females. Results of the CFAs provided support for the nine-item unidimensional solution in each of the four samples. Accordingly, Martin et al. (28, p. 359) suggested that the nine-item unidimensional model was “more parsimonious and conceptually clear than a two-factor model” and recommended that others should begin to utilize the nine-item unidimensional version of the SPAS.
The recommendation of Martin et al. (28) may be premature. Martin et al. (28) reported relative indices of fit but omitted other indices that would provide additional information needed to support the unidimensional model more completely. The CFAs were based on the responses of only women and the extent to which the proposed nine-item model fits the responses of men is unknown. The invariance of nine-item unidimensional model across gender also should be examined. Researchers have reported gender differences in mean SPAS scores (15,27), but inadequate attention has been directed toward potential gender differences in the factor structure. An invariance analysis will test the extent to which the factor structure underlying responses to the SPAS is equivalent across females and males (25). The invariance analysis illustrates whether responses to the SPAS have the same or different meaning for women and men, and it ultimately may contribute to a meaningful comparison and interpretation of mean SPAS scores across gender.
Further examination of the factorial validity and invariance of the SPAS is important because the understanding of social physique anxiety in physical activity environments is partly dependent upon a structurally valid and stable measure. The construct validity of the SPAS also requires further evaluation because establishing evidence of score meaning is a continual and evolving process (32). The present study, therefore, had five purposes that further tested the factorial validity, factorial invariance, and construct validity of the SPAS. We first tested whether a two-factor correlated solution to the original 12-item version of the SPAS was substantively meaningful or a methodological artifact representing positively and negatively worded items. The test was performed using the CFA methodology described by Marsh (26) and Tomás and Oliver (39). The two-factor correlated model was tested because it is statistically equivalent to the higher-order model, but unlike the higher-order model it is identified in covariance modeling. The second purpose involved assessing the factorial validity of the nine-item unidimensional model to the SPAS in a sample of women and men. The third purpose was to examine whether modifying the number of items based on both standardized residuals and item content would improve the factorial validity of the SPAS. The fourth purpose was to evaluate the factorial invariance of the SPAS across gender according to the multi-step procedure described by Jörsekog and Sörbom (19). The fifth purpose involved performing correlation analyses between SPAS scores and measures of theoretically related constructs to provide convergent and discriminant evidence of construct validity (32).