Fig. 2.
Final model estimates (males). Standardized path estimates with confidence intervals from the reduced two-factor common pathway model for RSA (respiratory sinus arrhythmia), HR1, HR2 (heart rate), SCL (skin conductance level) and NS-SCR (non-specific skin conductance) in 9–10 year old twins. Common additive genetic factors (A), shared environmental factors (C), and non-shared environmental factors (E) are depicted in circles. Ovals denote the two latent factors (i.e., Factor 1: sympathetic activity and Factor 2: parasympathetic activity). Measured variables are depicted in rectangles. As: additive genetic residual variance specific to each measure, likewise for shared environment (Cs), and non-shared environment (Es)