Cross-cultural Invariance Of The Mental Toughness Index Among American And Mexican Athletes

The popularity of mental toughness (MT) in English-speaking countries is well recognized. However, its worldwide cultural relevance remains to be fully disclosed. Gucciardi et al. (2016) and Morgan et al. (2018), using the Mental Toughness Index (MTI), reported intra-cultural invariance of MT in Australasia and in the U.S. and Greece, respectively. To date, there has been no effort to unearth the degree of the universality of the term between Mexico and USA via MTI. PURPOSE: To examine the invariance of MT across two different cultural groups of athletes and to further validate MTI. METHODS: The MTI was completed by 97 Mexican and 173 US athletes. The MTI consisted of eight items with a seven-point response scale. The U.S. samples consisted of roughly half male and half female athletes, whereas the Mexican was predominantly male (64%). The U.S. sample consisted of athletes from a number of sports, such as American football, basketball, baseball, and softball. Half of the Mexican sample reported playing soccer and almost all other sports had fewer than five athletes. Invariance testing was conducted using multiple group confirmatory factor analysis with increasingly restrictive models. We first fitted a unidimensional model within each sample to ensure good model-data fit. Then we estimated configural (equal number of dimensions), metric (configural + equal loadings), and scalar invariance models (metric + equal intercepts). Scalar invariance is the minimum type of invariance to infer cross cultural equality. To evaluate the model-data fit, we used the comparative fit index (CFI), root mean square error of approximation (RMSEA), and the differences between these indices for increasingly restrictive models. RESULTS: The model-data fit in both samples was very good (CFIGreek = .984, RMSEAGreek = .08; CFIMex = .998, RMSEAMex = .03). The scalar invariance model was selected as the best fitting (CFAscalar = .908, RMSEAscalar = .08) but with a slightly different item intercept for two items (Item 4, < .5; Item 7, < .3). CONCLUSION: These analyses support partial scalar invariance of MT. As such, the analysis establishes a common metric of MT across samples, which allows comparisons to be made on their MT scores.