Abstract

An extensive body of research has investigated links between perfectionism and 2 motivation, yet the underlying mechanisms linking these psychological characteristics 3 have been underexplored. In this study, we used an integrative modelling approach to 4 examine associations between dimensions of perfectionism (i.e., personal standards 5 [PSP] and concerns over mistakes [CMP]), mental toughness (MT), and motivational 6 orientations (i.e., self- [SDM] and non-self-determined motivation [NSDM]). Based on a 7 sample of 318 male (n = 218) and female (n = 100) tennis players (Mage = 17.61, SD = 8 2.41), fit indices derived from structural equation modelling supported a partially 9 mediated model. Residual PSP associated positively with MT (β = .74) and SDM (β = 10 .40), and negatively with NSDM (β = -.22). Conversely, residual CMP associated 11 negatively with MT (β = .14) and SDM (β = -.19), and positively with NSDM (β = .73). 12 Mental toughness was positively associated with SDM (β = .28), but was unrelated to 13 NSDM (β = .07). The relationship between residual PSP and SDM was partially 14 mediated by MT (standardized indirect effect: 95% CI = .19, .46). The findings of this 15 study support research linking dimensions of perfectionism with motivational 16 orientations and offers preliminary evidence on the mediating role of MT in the 17 association between these psychological constructs. With emerging research 18 supporting the capacity to develop MT through targeted interventions, the findings are 19 discussed alongside salient implications.