Debiased J-band linear polarization degree as a function of spectral type. Objects with v sin i ≥ 60 km s^-1 are plotted as black dots, and sources with slower spectroscopic rotational velocities are indicated with gray dots. Binary objects are indicated with triangles. Encircled symbols stand for linearly polarized sources. The two extra objects taken from Zapatero Osorio et al. (2011) (v sin i <  50 km s^-1) are shown with diamonds.