Age of the children

N

SD

M

F

Sig.

seven-year-olds

144

0.51

2.07

41.84

0.000

eight-year-olds

176

0.62

2.10

nine-year-olds

229

0.55

1.97

ten-year-olds

254

0.55

1.88

eleven-year-olds

366

0.52

1.79