Table 3: Standardized regression parameters for two-way and three-way moderation models.

StepModel 1Model 2Model 3
Fluid ability Crystallized ability Fluid ability Crystallized abilityFluid abilityCrystallized ability
𝛽 CI (95%) 𝛽 CI (95%) 𝛽 CI (95%) 𝛽 CI (95%) 𝛽 CI (95%) 𝛽 CI (95%)

N F C × a g e −.03−0.370.24−.04−0.410.24−.05−0.430.23−.01−0.380.32
C A E × a g e −.05−0.430.20−.05−0.450.24−.05−0.460.23.01−0.360.39
C A E × N F C −.09−0.430.10.00−0.280.29
C A E × N F C × a g e .09−−0.070.45

Note: the regressions were stepwise conducted, entering the respective set of independent variables in step 1, and their corresponding interaction terms in step 2 and 3. All models were run separately for fluid and crystallized ability as dependent variables. Model 1 shows the results for the two-way interaction of age and need for cognition; model 2 shows the two-way interaction of age and cognitive activity engagement; model 3 shows the results of testing for the three-way interaction. Significant parameters are shown in bold. Keys: age = age in years; NFC = need for cognition; CAE = cognitive activity engagement.