Table 2 Estimate and standard error (s.e.) of fixed effects in mixed models predicting participants’ partner choices, Prisoner’s Dilemma Game behaviour and beliefs about partner behaviour.

Intercept

−2.39 (0.25)^***

−3.26 (0.55)^***

−2.26 (0.18)^***

−2.86 (0.43)^***

−2.72 (0.34)^***

−0.94 (0.13)^***

−1.06 (0.33)^**

−1.11 (0.28)^***

Age group: 8 & 9

1.70 (0.66)^**

0.44 (0.57)

0.49 (0.29)

−0.62 (0.48)

−0.47 (0.26)

Condition: Disadvantageous

0.82 (0.68)

0.41 (0.56)

−0.01 (0.35)

−0.19 (0.46)

0.00 (0.31)

Condition: Equal

0.60 (0.68)

0.14 (0.57)

0.17 (0.35)

0.28 (0.45)

0.20 (0.31)

Gender: Male

0.47 (0.39)

0.18 (0.29)

0.21 (0.29)

0.07 (0.26)

0.06 (0.26)

Age group x Condition: 8 & 9 x Disadvantageous

−2.22 (0.94)^*

−0.27 (0.78)

0.36 (0.67)

Age group x Condition: 8 & 9 x Equal

−1.57 (0.94)

0.31 (0.78)

−0.12 (0.67)

Partner choice: Rejector

1.21 (0.73)

0.35 (0.26)

−1.01 (0.65)

−0.23 (0.23)

Age group x Partner choice: 8 & 9 x Rejector

−0.43 (0.91)

1.14 (0.81)

Condition x Partner choice: Disadvantageous x Rejector

−2.51 (1.17)^*

1.17 (0.88)

Condition x Partner choice: Equal x Rejector

−0.32 (1.01)

0.46 (0.88)

Age group x Condition x Partner choice: 8 & 9 x Disadvantageous x Rejector

2.10 (1.44)

−1.70 (1.19)

Age group x Condition x Partner choice: 8 & 9 x Equal x Rejector

−0.59 (1.30)

−0.61 (1.14)

Prisoner’s Dilemma Game decision: Cooperate

2.15 (0.25)^***

2.12 (0.25)^***

AIC

820.28

822.73

777.24

788.21

781.39

1184.90

1122.31

1111.53

BIC

830.10

862.00

787.05

856.88

815.72

1194.71

1195.88

1150.77

Log Likelihood

−408.14

−403.37

−386.62

−380.11

−383.69

−590.45

−546.15

−547.77

Number of trials

1001

1001

997

997

997

997

997

997

Number of participants

143

143

143

143

143

143

143

143

Variance: Participant ID (Intercept)

3.57

3.12

1.36

1.38

1.25

1.33

1.37

1.35