In functional-cognitive linguistics, as well as in semiotics, iconicity is the conceived similarity or analogy between the form of a sign (linguistic or otherwise) and its meaning, as opposed to arbitrariness (which is typically assumed in structuralist, formalist and generative approaches to linguistics). The principle of iconicity is also shared by the approach of linguistic typology. Iconic principles: Quantity principle: conceptual complexity corresponds to formal complexity Proximity principle: conceptual distance tends to match with linguistic distance Sequential order principle: the sequential order of events described is mirrored in the speech chain The use of quantity of phonetic material to iconically mark increased quality or quantity can be noted in the lengthening of words to indicate a greater degree, such as "". It is also common to use reduplication to iconically mark increase, as Edward Sapir is quoted, “The process is generally employed, with self-evident symbolism, to indicate such concepts as distribution, plurality, repetition, customary activity, increase of size, added intensity, continuance” (1921:79). This has been confirmed by the comparative studies of Key (1965) and Moravcsik (1978). This can be seen, for example, in Amharic, where täsäbbärä means "it was broken" and täsäbbabärä means that "it was shattered". Iconic coding principles may be natural tendencies in language and are also part of our cognitive and biological make-up. Whether iconicity is a part of language is an open debate in linguistics. For instance, Haspelmath has argued against iconicity, claiming that most iconic phenomena can be explained by frequency biases: since simpler meanings tend to be more frequent in the language use they tend to lose phonological material. Onomatopoeia (and mimesis more broadly) may be seen as a kind of iconicity, though even onomatopoeic sounds have a large degree of arbitrariness. Derek Bickerton has posited that iconic signs, both verbal and gestural, were crucial in the evolution of human language.