  One of the goals of the landscape program in string theory is to extract
information about the space of string vacua in the form of statistical
correlations between phenomenological features that are otherwise uncorrelated
in field theory. Such correlations would thus represent predictions of string
theory that hold independently of a vacuum-selection principle. In this paper,
we study statistical correlations between two features which are likely to be
central to any potential description of nature at high energy scales: gauge
symmetries and spacetime supersymmetry. We analyze correlations between these
two kinds of symmetry within the context of perturbative heterotic string
vacua, and find a number of striking features. We find, for example, that the
degree of spacetime supersymmetry is strongly correlated with the probabilities
of realizing certain gauge groups, with unbroken supersymmetry at the string
scale tending to favor gauge-group factors with larger rank. We also find that
nearly half of the heterotic landscape is non-supersymmetric and yet
tachyon-free at tree level; indeed, less than a quarter of the tree-level
heterotic landscape exhibits any supersymmetry at all at the string scale.
