(A) Schematic of the different predictions that each model provides for the probability contour lines for a pair of behaviors – uncorrelated single-trait model in orange vs. correlated full-repertoire approach in blue. By definition, the single-trait model cannot predict behavioral covariance either inter- or intra-species. (B) Behavioral traits averaged within-species (colored dots) for two specific behaviors show a positive correlation, which is explained by the full-repertoire model (in blue). Ellipses are centered at the coordinates representing the behavioral traits of the inferred ancestral state, with semi-major and semi-minor axes corresponding to the eigenvectors and values of the phylogenetic covariance matrix, restricted to the behaviors shown on the left. For comparison, the contour line inferred using the single-trait model is shown in orange (level curves at two standard deviations from the mean). (C) Behavioral traits for all individuals within a species show a negative correlation, for this particular pair of behaviors, in contrast to the positive correlation observed in the species means and predicted by the full model. Blue ellipses correspond to the contour probability levels coming from the individual covariance matrix of the full-repertoire model. Note that the predictions from the single-trait model must necessarily be uncorrelated.