“…Considering the influence of daily experiences in play, four kindergartens were selected to provide medium-sized wooden blocks in the classroom and conduct free play every day. The four kindergartens had the same (Ji 级) and category (Lei 类), and these kindergartens were often called R1C1 kindergartens (this meant that kindergartens of the top rank and category were regarded as the best) ( Pan et al, 2010 ). In the classroom, young children were randomly selected ( n = 228, 114 boys and 114 girls) in a total of 57 groups: 19 groups in younger class ( n = 76, mean age = 50.99 months, range: 41–59 months, SD = 4.17), 20 groups in the middle age class ( n = 80, mean age = 60.98 months, range: 46–71 months, SD = 5.68), and 18 groups in older class ( n = 72, mean age = 69.19 months, range: 62–76 months, SD = 3.80).…”