The concept of mental toughness has gained increasing importance among non-elite athletes for its psychological importance and explanatory power for a broad range of health-related behaviors. On the flip side, no study has focused so far on the psychological origins of mental toughness. Therefore, the aims of the present study were three-fold: to explore, to what extent psychological profiles of preschoolers at the age of five years predicted mental toughness scores and sleep disturbances at the age of 14 years, and to explore possible gender differences.

Nine years after their first assessment at the age of five years (preschoolers), a total of 77 adolescents (mean age: 14.35 years; SD = 1.22; 42% females) took part in the present follow-up study. At baseline, both parents and teachers completed the Strengths and Difficulties Questionnaire (SDQ), covering internalizing and externalizing problems, hyperactivity, negative peer relationships, and prosocial behavior. At follow-up, participants completed a booklet of questionnaires covering socio-demographic data, mental toughness, and sleep disturbances.

Preschoolers with high prosocial behavior and low internalizing and externalizing problems, as rated by parents and teachers, at the age of 14 years self-reported higher mental toughness and lower sleep disturbances. At the age of 14 years, and relative to their male counterparts, female participants reported lower MT scores and higher sleep disturbances.

The pattern of results suggests that mental toughness traits during adolescence have their origins during pre-school years.

The authors have not supplied their declaration of competing interest.