Scientific publications

@article{Safryghin2022a,

title = {Variable expression of linguistic laws in ape gesture: a case study from chimpanzee sexual solicitation},

author = {A. Safryghin and C. Cross and B. Fallon and R. Heesen and R. Ferrer-i-Cancho and C. Hobaiter},

url = {https://www.biorxiv.org/content/10.1101/2021.05.19.444810v3},

doi = {10.1098/rsos.220849},

year  = {2022},

date = {2022-01-01},

journal = {Royal Society Open Science},

volume = {9},

pages = {9220849},

abstract = {Two language laws have been identified as consistent patterns shaping animal behaviour, both acting on the organizational level of communicative systems. Zipf's law of brevity describes a negative relationship between behavioural length and frequency. Menzerath's law defines a negative correlation between the number of behaviours in a sequence and average length of the behaviour composing it. Both laws have been linked with the information-theoretic principle of compression, which tends to minimize code length. We investigated their presence in a case study of male chimpanzee sexual solicitation gesture. We failed to find evidence supporting Zipf's law of brevity, but solicitation gestures followed Menzerath's law: longer sequences had shorter average gesture duration. Our results extend previous findings suggesting gesturing may be limited by individual energetic constraints. However, such patterns may only emerge in sufficiently large datasets. Chimpanzee gestural repertoires do not appear to manifest a consistent principle of compression previously described in many other close-range systems of communication. Importantly, the same signallers and signals were previously shown to adhere to these laws in subsets of the repertoire when used in play; highlighting that, in addition to selection on the signal repertoire, ape gestural expression appears shaped by factors in the immediate socio-ecological context.},

keywords = {Menzerath's law, Zipf's law of abbreviation},

pubstate = {published},

tppubtype = {article}

}

@article{Heesen2019a,

title = {Linguistic laws in chimpanzee gestural communication},

author = {R. Heesen and C. Hobaiter and R. Ferrer-i-Cancho and S. Semple},

doi = {10.1098/rspb.2018.2900},

year  = {2019},

date = {2019-01-01},

journal = {Proceedings of the Royal Society B: Biological Sciences},

volume = {286},

pages = {20182900},

abstract = {Studies testing linguistic laws outside language have provided important insights into the organization of biological systems. For example, patterns consistent with Zipf's law of abbreviation (which predicts a negative relationship between word length and frequency of use) have been found in the vocal and non-vocal behaviour of a range of animals, and patterns consistent with Menzerath's law (according to which longer sequences are made up of shorter constituents) have been found in primate vocal sequences, and in genes, proteins and genomes. Both laws have been linked to compression-the information theoretic principle of minimizing code length. Here, we present the first test of these laws in animal gestural communication. We initially did not find the negative relationship between gesture duration and frequency of use predicted by Zipf's law of abbreviation, but this relationship was seen in specific subsets of the repertoire. Furthermore, a pattern opposite to that predicted was seen in one subset of gestures-whole body signals. We found a negative correlation between number and mean duration of gestures in sequences, in line with Menzerath's law. These results provide the first evidence that compression underpins animal gestural communication, and highlight an important commonality between primate gesturing and language.},

keywords = {Menzerath's law, Zipf's law of abbreviation},

pubstate = {published},

tppubtype = {article}

}

@article{Gustison2016a,

title = {Gelada vocal sequences follow Menzerath's linguistic law},

author = {M. L. Gustison and S. Semple and R. Ferrer-i-Cancho and T. Bergman},

doi = {10.1073/pnas.1522072113},

year  = {2016},

date = {2016-01-01},

journal = {Proceedings of the National Academy of Sciences USA},

volume = {13},

number = {19},

pages = {E2750–E2758},

abstract = {Identifying universal principles underpinning diverse natural systems is a key goal of the life sciences. A powerful approach in addressing this goal has been to test whether patterns consistent with linguistic laws are found in nonhuman animals. Menzerath’s law is a linguistic law that states that, the larger the construct, the smaller the size of its constituents. Here, to our knowledge, we present the first evidence that Menzerath’s law holds in the vocal communication of a nonhuman species. We show that, in vocal sequences of wild male geladas (Theropithecus gelada), construct size (sequence size in number of calls) is negatively correlated with constituent size (duration of calls). Call duration does not vary significantly with position in the sequence, but call sequence composition does change with sequence size and most call types are abbreviated in larger sequences. We also find that intercall intervals follow the same relationship with sequence size as do calls. Finally, we provide formal mathematical support for the idea that Menzerath’s law reflects compression—the principle of minimizing the expected length of a code. Our findings suggest that a common principle underpins human and gelada vocal communication, highlighting the value of exploring the applicability of linguistic laws in vocal systems outside the realm of language.},

keywords = {information theory, Menzerath's law},

pubstate = {published},

tppubtype = {article}

}

@article{Ferrer2012h,

title = {When is Menzerath-Altmann law mathematically trivial? A new approach},

author = {R. Ferrer-i-Cancho and A. Hernández-Fernández and J. Baixeries and Ł. Dębowski and J. Mačutek},

doi = {10.1515/sagmb-2013-0034},

year  = {2014},

date = {2014-01-01},

journal = {Statistical Applications in Genetics and Molecular Biology},

volume = {13},

number = {6},

pages = {633-644},

abstract = {Menzerath’s law, the tendency of Z (the mean size of the parts) to decrease as X (the number of parts) increases, is found in language, music and genomes. Recently, it has been argued that the presence of the law in genomes is an inevitable consequence of the fact that Z=Y/X, which would imply that Z scales with X as Z∼1/X. That scaling is a very particular case of Menzerath-Altmann law that has been rejected by means of a correlation test between X and Y in genomes, being X the number of chromosomes of a species, Y its genome size in bases and Z the mean chromosome size. Here we review the statistical foundations of that test and consider three non-parametric tests based upon different correlation metrics and one parametric test to evaluate if Z∼1/X in genomes. The most powerful test is a new non-parametric one based upon the correlation ratio, which is able to reject Z∼1/X in nine out of 11 taxonomic groups and detect a borderline group. Rather than a fact, Z∼1/X is a baseline that real genomes do not meet. The view of Menzerath-Altmann law as inevitable is seriously flawed.},

keywords = {genomes, Menzerath's law},

pubstate = {published},

tppubtype = {article}

}

@article{Ferrer2012f,

title = {The challenges of statistical patterns of language: the case of Menzerath's law in genomes},

author = {R. Ferrer-i-Cancho and N. Forns and A. Hernández-Fernández and G. Bel-Enguix and J. Baixeries},

doi = {10.1002/cplx.21429},

year  = {2013},

date = {2013-01-01},

journal = {Complexity},

volume = {18},

number = {3},

pages = {11-17},

abstract = {The importance of statistical patterns of language has been debated over decades. Although Zipf's law is perhaps the most popular case, recently, Menzerath's law has begun to be involved. Menzerath's law manifests in language, music and genomes as a tendency of the mean size of the parts to decrease as the number of parts increases in many situations. This statistical regularity emerges also in the context of genomes, for instance, as a tendency of species with more chromosomes to have a smaller mean chromosome size. It has been argued that the instantiation of this law in genomes is not indicative of any parallel between language and genomes because (a) the law is inevitable and (b) noncoding DNA dominates genomes. Here mathematical, statistical, and conceptual challenges of these criticisms are discussed. Two major conclusions are drawn: the law is not inevitable and languages also have a correlate of noncoding DNA. However, the wide range of manifestations of the law in and outside genomes suggests that the striking similarities between noncoding DNA and certain linguistics units could be anecdotal for understanding the recurrence of that statistical law.},

keywords = {genomes, Menzerath's law},

pubstate = {published},

tppubtype = {article}

}

@article{Ferrer2012g,

title = {Erratum to "Random models of Menzerath-Altmann law in genomes" (BioSystems 107 (3), 167-173)},

author = {R. Ferrer-i-Cancho and J. Baixeries and A. Hernández-Fernández},

doi = {10.1016/j.biosystems.2013.01.004},

year  = {2013},

date = {2013-01-01},

journal = {Biosystems},

volume = {111},

number = {3},

pages = {216-217},

keywords = {genomes, Menzerath's law},

pubstate = {published},

tppubtype = {article}

}

@article{Baixeries2012b,

title = {The parameters of Menzerath-Altmann law in genomes},

author = {J. Baixeries and A. Hernández-Fernández and N. Forns and R. Ferrer-i-Cancho},

doi = {10.1080/09296174.2013.773141},

year  = {2013},

date = {2013-01-01},

journal = {Journal of Quantitative Linguistics},

volume = {20},

number = {2},

pages = {94-104},

abstract = {The relationship between the size of the whole and the size of the parts in language and music is known to follow the Menzerath-Altmann law at many levels of description (morphemes, words, sentences,...). Qualitatively, the law states that the larger the whole, the smaller its parts, e.g. the longer a word (in syllables) the shorter its syllables (in letters or phonemes). This patterning has also been found in genomes: the longer a genome (in chromosomes), the shorter its chromosomes (in base pairs). However, it has been argued recently that mean chromosome length is trivially a pure power function of chromosome number with an exponent of -1. The functional dependency between mean chromosome size and chromosome number in groups of organisms from three different kingdoms is studied. The fit of a pure power function yields exponents between -1.6 and 0.1. It is shown that an exponent of -1 is unlikely for fungi, gymnosperm plants, insects, reptiles, ray-finned fishes and amphibians. Even when the exponent is very close to -1, adding an exponential component is able to yield a better fit with regard to a pure power-law in plants, mammals, ray-finned fishes and amphibians. The parameters of the Menzerath-Altmann law in genomes deviate significantly from a power law with a -1 exponent with the exception of birds and cartilaginous fishes.},

keywords = {genomes, Menzerath's law},

pubstate = {published},

tppubtype = {article}

}

@article{Baixeries2012a,

title = {Random models of Menzerath-Altmann law in genomes},

author = {J. Baixeries and A. Hernández-Fernández and R. Ferrer-i-Cancho},

doi = {10.1016/j.biosystems.2011.11.010},

year  = {2012},

date = {2012-01-01},

journal = {Biosystems},

volume = {107},

pages = {167-173},

abstract = {Recently, a random breakage model has been proposed to explain the negative correlation between mean chromosome length and chromosome number that is found in many groups of species and is consistent with Menzerath-Altmann law, a statistical law that defines the dependency between the mean size of the whole and the number of parts in quantitative linguistics. Here, the central assumption of the model, namely that genome size is independent from chromosome number is reviewed. This assumption is shown to be unrealistic from the perspective of chromosome structure and the statistical analysis of real genomes. A general class of random models, including that random breakage model, is analyzed. For any model within this class, a power law with an exponent of -1 is predicted for the expectation of the mean chromosome size as a function of chromosome length, a functional dependency that is not supported by real genomes. The random breakage and variants keeping genome size and chromosome number independent raise no serious objection to the relevance of correlations consistent with Menzerath-Altmann law across taxonomic groups and the possibility of a connection between human language and genomes through that law.},

keywords = {genomes, Menzerath's law},

pubstate = {published},

tppubtype = {article}

}

@article{Ferrer2009e,

title = {The self-organization of genomes},

author = {R. Ferrer-i-Cancho and N. Forns},

doi = {10.1002/cplx.20296},

year  = {2009},

date = {2009-01-01},

journal = {Complexity},

volume = {15},

number = {5},

pages = {34-36},

abstract = {Menzerath-Altmann law is a general law of human language stating, for instance, that the longer a word, the shorter its syllables. With the metaphor that genomes are words and chromosomes are syllables, we examine if genomes also obey the law. We find that longer genomes tend to be made of smaller chromosomes in organisms from three different kingdoms: fungi, plants, and animals. Our findings suggest that genomes self-organize under principles similar to those of human language.},

keywords = {genomes, Menzerath's law},

pubstate = {published},

tppubtype = {article}

}