Stellar mass-azimuthal anisotropy correlation. The top panel shows the occurrence of galaxies per bin of stellar mass with isotropic, radial and tangential orbits (circle, triangle, and squared symbols, respectively), normalized to the total number of galaxies per 0.5 dex bin of stellar mass. The mass unit is M_⊙. The starred symbol is for the Milky Way. The solid line is the most likely linear model of the mass-anisotropy relation given by Eq. (6).