This paper discusses three related claims. The first claim is that the expressive limitations of iconic and indexical communication and cognition are reasonably measured by their minimal arbitrariness across three distinct dimensions—resemblance, alternative, and acquisition—when compared to the high measures of resemblance, alternative, and acquisition arbitrariness of symbolic communication and cognition. The second claim is that the ways that developed symbolic communication systems ground symbols to the world can also help explain how iconic and indexical communication systems underwrote the generation (...) of symbols in the first place. And the third claim is that contemporary accounts about the origins of symbolic communication would benefit from keeping in mind the differences between resemblance arbitrariness, alternative resemblance, and acquisition resemblance as each is exemplified by icons, indexes, and symbols. (shrink)