  The emergence of the objective classical world from the quantum behavior of
microscopic constituents is not fully understood. Models based on decoherence
and the principle of quantum Darwinism, which attempt to provide such an
explanation, require system-bath interactions in a preferred basis. Thus, the
generic emergence of objectivity in the position basis, as observed in the real
world remains unexplained. In this Letter, we present a no-go theorem based on
the principle of no-faster-than-light communication, showing that interactions
between internal degrees of freedom unavoidably cause system wave functions to
branch in the position basis. We apply this result to a spin decoherence model
to demonstrate that a generic thermal spin-1/2 bath redundantly records
information about the position of a spin-1/2 particle. Notably, the model does
not assume any preferred spin interaction. These findings represent a
compelling demonstration of the generic emergence of objectivity in the
position basis.
