The first hypothesis of correlated influences was tested using a Cholesky decomposition (44;46). In this model, A, C and E influence RSI and PSI. Influences on RSI (from Figure 1, Panel A) are those that are overlapping with influences on PSI (A21, C21 and E21) and those that are specific to RSI (A22, C22 and E22). For instance, the total genetic variance in RSI is equal to genetic factors that are specific to RSI and those shared between RSI and PSI ((A21)2 + (A22)2).
