  The two-pion exchange interaction between constituent quarks is shown to
enhance the effect of the the isospin dependent spin-spin component of the
one-pion exchange interaction, and to cancel out its tensor component. It
therefore provides a partial explanation for the phenomenological observation
that the hyperfine interaction between constituent quarks is well described by
a flavor dependent spin-spin interaction, which is attractive at short and
repulsive at long range. The spin-orbit component of the two-pion exchange
interaction is stronger than and has the opposite sign from that associated
with the linear confining interaction in the $P-$shell multiplets.
