  Colexification refers to the phenomenon of multiple meanings sharing one word
in a language. Cross-linguistic lexification patterns have been shown to be
largely predictable, as similar concepts are often colexified. We test a recent
claim that, beyond this general tendency, communicative needs play an important
role in shaping colexification patterns. We approach this question by means of
a series of human experiments, using an artificial language communication game
paradigm. Our results across four experiments match the previous
cross-linguistic findings: all other things being equal, speakers do prefer to
colexify similar concepts. However, we also find evidence supporting the
communicative need hypothesis: when faced with a frequent need to distinguish
similar pairs of meanings, speakers adjust their colexification preferences to
maintain communicative efficiency, and avoid colexifying those similar meanings
which need to be distinguished in communication. This research provides further
evidence to support the argument that languages are shaped by the needs and
preferences of their speakers.
