Objective
This study sought to identify psychological factors associated with the severity of the yips. Although prior research has investigated antecedents of yips onset, the reasons why symptoms worsen or escalate have not been examined sufficiently, leaving an important gap for targeted assessment and intervention.
Methods
Ten collegiate baseball players affected by the yips completed 10 throws each from 45 ft and 90 ft. Psychological factors—reinvestment, perfectionism, competitive trait anxiety, and pre-throw state anxiety—were dichotomized at the sample mean (high ≥ mean; low < mean). Between-group differences in performance were evaluated using nonparametric tests (Mann-Whitney U test; where appropriate, Kruskal-Wallis test with tied-rank adjustment).
Results
At 45 ft, a significant group difference was observed for reinvestment (Mann-Whitney U = 2.5, z = −2.044, exact p = .038; asymptotic p = .041). Competitive trait anxiety was also significant (Kruskal-Wallis H = 7.257, df = 2, p = .027). Pre-throw state anxiety and perfectionism were not significant at 45 ft, and no comparisons at 90 ft reached significance (all p > .05).
Conclusions
These findings indicate that reinvestment and competitive trait anxiety may contribute to the worsening of yips symptoms. By contrast, although other psychological factors and the 90-ft condition did not yield statistically significant differences, several comparisons exhibited relatively large effect sizes, and insufficient statistical power cannot be ruled out. Future research should increase sample size and conduct analyses that consider relations among psychological factors (e.g., mediation and interaction) in order to more precisely identify the psychological determinants most closely linked to the aggravation and escalation of yips symptoms.