We (1) propose that evidence linking grit and performance is mixed because the measure used to assess grit—the Short Grit (Grit-S) scale (2)—captures only perseverance, not passion, whereas the definition of grit encompasses both perseverance and passion (3). Our studies find that the combination of perseverance (measured through the whole Grit-S scale) and passion (measured through the passion attainment scale) predicted higher performance. In their letters, Guo et al.(4) and Cred é (5) suggest that the Grit-S scale should be treated as reflecting two factors. Credé (5) subsequently advocates for and Guo et al.(4) conducts separate analyses for each supposed subfacet of the Grit-S scale (called “perseverance of effort” and “consistency of interests”). In this response, we provide additional evidence that the Grit-S scale is unidimensional. That is, there is no validity to the claims by Guo et al.(4) and Cred e (5) that the Grit-S scale is composed of two subfactors. As a result, the analyses advocated by both letters are inappropriate. Instead, the Grit-S scale should be treated as unidimensional, which is how we conducted our original analyses (1).

A careful examination of the Grit-S scale items reveals two important points. First, closely reading the scale items highlights that the Grit-S scale captures perseverance alone and does not capture passion. Passion, defined as “a strong feeling toward a personally important value/preference that motivates intentions and behaviors to express that value/preference”(1), is not captured in any of the Grit-S scale items (Table 1, upper section). For example, Guo et al.(4) and Credé (5) claim that the items “I often set a goal but later choose to pursue a different one” and “New ideas and projects sometimes distract me from