  Recently there has been considerable interest in the subject of molecules,
which are weakly bound states of hadron pairs. The question of the existence of
molecules is closely related to the more general problem of the determination
of low energy hadron-hadron scattering amplitudes, which is widely believed to
require nonperturbative methods. In this contribution we report on quark model
calculations using a simple perturbative scattering mechanism, one gluon
exchange followed by constituent interchange. We refer to the associated
diagrams as ``quark Born diagrams". For the cases chosen to isolate this
mechanism, I=2 $\pi\pi$, I=3/2 K$\pi$ and KN the results are usually in good
agreement with experimental S-wave scattering amplitudes given standard
potential model parameters, and for NN we find perturbative results very
similar to the nonperturbative hard cores of Oka and Yazaki. We also discuss
our findings for other less familiar channels; these include predictions of
vector-vector bound states, one of which may be the $\theta(1710)$.
