General intelligence was associated with academic achievement but not fitness in adolescents after one year

Abstract

Aim: This study investigated whether general intelligence could predict physical fitness and academic achievements one year later.

Methods: We recruited 129 Spanish adolescents (57.4% boys) with a mean age of 13.6 ± 0.7 years old from a convenience sample of a single public-funded school. The first step was to assess general intelligence during the 2015-2016 school year using the D48 nonverbal test. A year later, we collected data on fitness and academic achievements. Cardiorespiratory fitness was measured with the 20-m endurance shuttle run test, muscular strength with the standing long jump and flexibility with the sit and reach test. Academic achievement was measured using school grades. The findings were assessed using three models with different variables.

Results: One year later, general intelligence at baseline was marginally significantly associated with flexibility (p = 0.079) and mathematics (p = 0.084) in the first model, with mathematics (p = 0.029) and geography and history (p = 0.016) in the second model and with geography and history (p = 0.022) in the third model. All the analyses were controlled by age, sex, fitness and academic achievement.

Conclusion: General intelligence may not predict fitness, but it may predict academic achievements in adolescents one year later. Further studies are needed to examine our findings.

Keywords: Cognition; Endurance; Flexibility; Muscle strength; School grades.