  While it is generally accepted, in the framework of Poincare gauge theory,
that the Lorentz connection couples minimally to spinor fields, there is no
general agreement on the coupling of the translational gauge field to fermions.
We will show that the assumption that spinors carry a full Poincare
representation leads to inconsistencies, whose origins will be traced back by
considering the Poincare group both as the contraction of the de Sitter group,
and as a subgroup of the conformal group. As a result, the translational fields
do not minimally couple to fermions, and consequently, fermions do not possess
an intrinsic momentum.
