Age of the children

N

SD

M

F

Sig.

seven-year-olds

144

0.34

1.89

2.45

0.011

eight-year-olds

176

0.36

1.84

nine-year-olds

229

0.36

1.84

ten-year-olds

254

0.37

1.83

eleven-year-olds

366

0.39

1.80