  In the last decade, near-infrared imaging has highlighted the decoupling of
gaseous and old stellar disks: the morphologies of optical (Population I)
tracers compared to the old stellar disk morphology, can be radically
different. Galaxies which appear multi-armed and even flocculent in the optical
may show significant Grand-Design spirals in the near-infrared. Furthermore,
the optically determined Hubble classification scheme does not provide a sound
way of classifying dust-penetrated stellar disks: spiral arm pitch angles (when
measured in the near-infrared) do not correlate with Hubble type. The
dust--penetrated classification scheme of Block & Puerari provides an
alternative classification based on near-infrared morphology, and which is thus
more closely linked to the dominant stellar mass component. Here we present
near--infrared K band images of 14 galaxies, on which we have performed a
Fourier analysis of the spiral structure in order to determine their
near-infrared pitch angles and dust--penetrated arm classes. We have also used
the rotation curve data of Mathewson et al. to calculate the rates of shear in
the stellar disks of these galaxies. We find a correlation between
near-infrared pitch angle and rate of shear: galaxies with wide open arms (the
$\gamma$ class) are found to have rising rotation curves, while those with
falling rotation curves belong to the tightly wound $\alpha$ bin. The major
determinant of near-infrared spiral arm pitch angle is the distribution of
matter within the galaxy concerned. The correlation reported in this study
provides the physical basis underpinning spiral arm classes in the
dust-penetrated regime and underscores earlier spectroscopic findings by
Burstein and Rubin that Hubble type and mass distributions are unrelated.
