  The temperature dependence of the magnetic susceptibility, \chi (T), is
investigated for one-dimensional interacting electron systems at
quarter-filling within the Kadanoff-Wilson renormalization-group method.
  The forward scattering on the same branch (the g_4-process) is examined
together with the backward (g_1) and forward (g_2) scattering amplitudes on
opposite branches.
  In connection with lattice models, we show that \chi (T) is strongly enhanced
by the nearest-neighbor interaction, an enhancement that surpasses one of the
next-nearest-neighbor interaction.
  A connection between our predictions for \chi (T) and experimental results
for \chi (T) in quasi-one-dimensional organic conductors is presented.
