The Law of Brevity in Macaque Vocal Communication is not an Artefact of Analysing Mean Call Durations^∗

Abstract

Words follow the law of brevity, i.e. more frequent words tend to be shorter. From a statistical point of view, this qualitative definition of the law states that word length and word frequency are negatively correlated. Here the recent finding of patterning consistent with the law of brevity in Formosan macaque vocal communication (Semple et al., 2010) is revisited. It is shown that the negative correlation between mean duration and frequency of use in the vocalizations of Formosan macaques is not an artifact of the use of a mean duration for each call type instead of the customary 'word' length of studies of the law in human language. The key point demonstrated is that the total duration of calls of a particular type increases with the number of calls of that type.The finding of the law of brevity in the vocalizations of these macaques therefore defies a trivial explanation.

Linguistic laws of brevity: conformity in Indri indri

“…When controlling for the phrase duration, we also found that more common phrase types (DP2 and DP3) were shorter than the infrequent longer phrases. Our results are in line with previous findings on other primate species vocal (Formosan macaque: Semple et al 2010Semple et al , 2013 and gestural communication (western gorilla: Genty and Byrne 2010; chimpanzee: Heesen et al 2019). This investigation, endorsing recent findings on gibbons (Huang et al 2020), also corroborates evidence that primate songs conform to the Zipf's law of brevity and broadens findings on the prevalence of this feature in communication systems.…”

“…Studies of non-human primate vocal behavior showed mixed evidence for conformity with the above-mentioned laws. Indeed, besides humans (Zipf 1945;1949;Strauss et al 2007), vocalizations of the Formosan macaque (Macaca cyclopis: Semple et al 2010Semple et al , 2013, geladas (Theropithecus gelada: Gustison et al 2016), eastern chimpanzees (Pan troglodytes schweinfurthii : Fedurek et al 2017), and mountain gorillas (Gorilla beringei beringei: Watson et al 2020), as well as the gestural communication of western gorillas (Gorilla gorilla gorilla: Genty and Byrne 2010) and chimpanzees (Heesen et al 2019), have shown evidence for compression. Conversely, the vocal repertoires of at least two new world primate species have been found to deviate from the pattern predicted by compression principles (Callithrix jacchus, Cacajao melanocephalus: Bezerra et al 2011).…”

Hahahahaha, Duuuuude, Yeeessss!: A two-parameter characterization of stretchable words and the dynamics of mistypings and misspellings

“…These distributions tend to generally follow Zipf's brevity law, or law of abbreviation, which states that more frequent words tend to be shorter [31,32]. This law has been found to hold for many different languages, and possibly even for communication between other primates [31][32][33][34][35][36]. However, we find this law is not always strictly followed.…”

Compression principle and Zipf’s Law of brevity in infochemical communication

“…One paradigmatic case is the description of DNA structure [14,15] where similarities between the genetic code and the verbal language have been validated [16]. Language patterns can be theorized and quantitatively measured with the use of linguistic laws, statistical regularities shared across human communication [17,18], and also discovered in biological systems [19] as diverse as the vocalizations [20][21][22][23][24] and gestures of other primates [25], genomics [26,27], proteomics [28][29][30][31] and chemical communication systems [32].…”