Table 1.

Differences in explained variance with and without latent interaction

	Original model			Latent moderation model				Difference
Model	βYX1	βYX2	R 2	βYX1	βYX2	βX1X2	R 2	ΔR2
No covariates	0.452	0.290	0.074	0.372	0.293	0.486	0.110	0.036
Age	0.426	0.030	0.038	0.358	0.048	0.479	0.077	0.040
Age, sex	0.416	0.019	0.036	0.297	−0.050	0.461	0.060	0.025
Age, sex, and education	0.391	0.024	0.032	0.227	−0.273	0.483	0.050	0.017

Note. R² and ΔR² (i.e., change in R²) were calculated using the formula provided by Maslowsky et al. (2015). β_YX1: SEM model parameter for regression path to verbal learning slope latent factor from latent factor WM (X1). β_YX2: SEM model parameter for regression path to verbal learning slope factor from latent factor HC (X2). β_X1X2: Covariance between the factors for HC and WM. R² values reflect only variance in verbal learning slope factor explained by the two latent factors WM (X1) and HC (X2), and by their latent interaction. ΔR²: difference in R² values with and without latent interaction. In covariate models, R² estimates reflect the inclusion of age, sex, and education.