Table 1 Descriptive statistics and correlations among the variables

Individual level

 Gender

—

—

—

 Age

10.97

0.98

 − 0.05

1

 Social support

5.93

1.05

 − 0.02

0.14^***

1

 Moral disengagement

1.67

0.47

0.01

 − 0.08^**

 − 0.29^***

1

 Defender self-efficacy

5.46

1.37

 − 0.46

0.07^**

0.39^***

 − 0.28^***

1

 Reinforcer behavior

0.14

0.39

 − 0.05

0.06^*

 − 0.14^***

0.22^***

 − 0.11^***

1

 Defender behavior

3.12

0.99

0.02

0.03

0.28^***

 − 0.23^***

0.37^***

 − 0.11^***

1

 Outsider behavior

1.51

0.99

 − 0.06^*

0.06^**

 − 0.16^***

0.19^***

 − 0.10^**

0.31^***

 − 0.03

1

Class level

 Grade

—

—

—

 Class size

42.13

3.48

 − 0.06^*

1

 Class moral disengagement

1.67

0.18

 − 0.33^***

0.00

1

 Class defender self-efficacy

5.46

0.37

0.24^***

 − 0.13^***

 − 0.55^***

1