Background
The construct of grit, perseverance and passion for long term goals, was devised to explain differences in educational and vocational outcomes (Duckworth et al., 2007). Researchers have established several measures of grit, including the Grit-O (Duckworth et al., 2007), the Grit-S (Duckworth & Quinn, 2009), and the Grit-5 (Lechner et al., 2019). However, research regarding the structural validity and measurement invariance of these scales is lacking.
Hypotheses/Research Questions
In the current study, we differentiated grit from contentiousness and compared the scales’ factor structures and measurement invariance across age and educational attainment.
Sample Characteristics and Sample Size
Participants were US residents (n = 1,915) who volunteered to complete personality measures on OpenPsychometrics.com. The sample's ages ranged between 14 and 78 (Mage= 25.74, SD = 12.23), mostly female (67.3%), and primarily high school (45.11%) and have a high school degree (45.11%).
Design
Measures included the Grit-O, which contains items that comprise the Grit-S and Grit-5.
Results
According the Kline’s (2016) method, only the bifactor structure of the Grit-O fit the data; however, this model failed to demonstrate measurement invariance. The Grit-5 and Grit-S single-factor, two-factor, and bifactor models passed Kline’s method and demonstrated strong configural, metric, and scalar invariance across educational attainment. However, no model demonstrated metric invariance across age groups; thus, our results indicated that grit should not be compared among individuals from different age groups.
Scientific Contribution
While the bifactor model of the Grit-S produced the best fit, the parameter estimates for the perseverance subscale were low or negative; therefore, only total scores and consistency subscale scores on the Grit-S may be appropriate measures of grit and its components. In contrast, the bifactor Grit-O suggested that the total score and both subscale scores on that measure provide meaningful information. Research limitations and additional recommendations are discussed.