Weak universal forces: The discriminatory function of case in differential object marking systems

Standard typological methods are designed to test hypotheses on strong universals
that broadly override all other competing universal and language-specific forces.
In this paper, I argue that there exist also weak universal forces. Weak universal
forces systematically operate in the course of development but then interact with,
or are even subsequently overridden by, other processes such as analogical exten-
sion, persistence effects from the source function, etc. This, in turn, means that
there can be statistically significant evidence for violations at the synchronic level
and, accordingly, only a weak positive statistical signal. But crucially, the absence
of statistical prima-facie evidence for such forces does not amount to evidence for
their absence. The assumption that there are also weak universal forces that affect
language evolution goes in line with the view that human cognition in general and
language acquisition in particular are constrained by probabilistic biases of differ-
ent range, including weak ones (cf. Thompson et al. 2016). By way of example, the
present paper claims that the discriminatory function of case in differential object
marking (DOM) systems is a weak universal: It keeps appearing in historically, syn-
chronically and typologically very divergent constellations but is often overridden
by other processes in further developments and is, therefore, not significant at the
synchronic level in a large sample.