The relative age effect on fundamental movement skillsl in Chinese children aged 3-5 years

The cut-off date in the education system causes a relative age difference, with developmental advantages for children who are born on the "early side" of the cut-off date and disadvantages for those born later, which is known as the relative age effect (RAE). Very few studies have examined whether there is a RAE on the development of fundamental movement skills (FMSs) in preschool children, and no studies have been conducted in China. The purpose of this study is to identify whether a RAE exists on FMS in Chinese preschool children, comparing RAEs according to gender and age.

From a total of 378 invited preschool children regularly registered at one Chinese kindergarten, a total of 288 healthy and typically developing preschoolers (4.33 ± 0.84 years-old; 56.6% boys) were included in this study. All children were required to take part in anthropometry and FMS assessments. Analysis of covariance (ANCOVA) was applied to examine the difference in each of the FMS items across quarter categories, year and gender groups, controlling for body mass index (BMI).

For the overall sample, the data show the significant main effects on the quarter of birth factor in locomotor skills (LC; F (3, 265) = 2.811, p = 0.04, η_p² = 0.031), object control skills (OB; F (3, 265) = 6.319, p = 0.04, η_p² = 0.031), and total test score (TTS; F (3, 265) = 5.988, p = 0.001, η_p² = 0.063). There were also significant differences in the age effect on all the domains of FMS (F_LC (2, 265) = 100.654, p < 0.001, η_p² = 0.432; F_OB (2, 265) = 108.430, p < 0.001, η_p² = 0.450; F_TTS (2, 265) = 147.234, p < 0.001, η_p² = 0.526) but a gender effect only in LC (F (1, 265) = 20.858; p < 0.001; η_p² = 0.073). For gender and quarter of birth groups, RAEs in LC only exists in girls. Moreover, regarding age and quarter of birth factors, RAEs are only found at younger ages.

This study suggests the existence of RAEs in the FMS of Chinese preschool children. Teachers need to be aware of the effect of RAEs on the FMS when approaching development, evaluation, and teaching approaches in preschools.