  We studied the Co valences and spin states in electron-doped
LaCo$_{1-y}$Te$_{y}$O$_3$ by measuring x-ray absorption spectra and electron
spin resonance. The low-temperature insulating state involves the low-spin
Co$^{3+}$ ($S=0$) and the high-spin Co$^{2+}$ state, which is described by
$g=3.8$ and $j_{\rm eff}=1/2$. The results, in concurrence with the
electron-hole asymmetry confirmed in electrical resistivity, coincide with a
spin-blockade phenomenon in this system. Further, we discuss the $g$ factor in
terms of the strong covalent-bonding nature and consider multiple origins of
this phenomenon.
