Twenty vs Ten: HSE Researcher Examines Origins of Numeral System in Lezgic Languages
It is commonly believed that the Lezgic languages spoken in Dagestan and Azerbaijan originally used a vigesimal numeral system, with the decimal system emerging later. However, a recent analysis of numerals in various dialects, conducted by linguist Maksim Melenchenko from HSE University, suggests that the opposite may be true: the decimal system was used originally, with the vigesimal system developing later. The study has been published in Folia Linguistica.
How many fingers do you need to count to forty? That depends on the language you are counting in. In Russian and most European languages, the decimal counting system is standard, with numbers like 40 formed as 4 × 10, 60 as 6 × 10, and so on. A vigesimal system is based on the number 20, so 60 is expressed as 3 × 20, and 50 as 2 × 20 + 10.
Counting by tens or twenties is not just a matter of convenience—it also has historical roots. In the Lezgic group of languages—which includes Lezgian, Tabasaran, Aghul, and Rutul—both numeral systems are found: some dialects use a base-10 system with numbers like 10, 20, 30, while others follow a base-20 system with numbers like 20, 40, 60, and so on. Until recently, it was believed that the vigesimal system in these languages was more ancient, but a new study by linguists at HSE University challenges this assumption.
Maksim Melenchenko, Research Assistant at the Linguistic Convergence Laboratory of the HSE Faculty of Humanities, analysed numerals in nine Lezgic languages and concluded that the decimal system may have existed earlier, rather than being a later borrowing. In some languages, he discovered supposedly archaic forms of the number 40, suggesting an alternative development of the counting system. These forms are called archaic because certain features make them appear older than modern numerals.
Maksim Melenchenko
'For the number 40, some Lezgic languages unexpectedly use a decimal system: even in villages where counting by twenties is common, 40 is expressed as 4 × 10. This may indicate that the overall system of numeral formation has changed, but earlier forms of the number forty have persisted in the language, reflecting an older numeral system,' explains Melenchenko.
Another detail noted by the linguist is the special suffixes found on all decimal numerals from 30 to 90. In some languages where these numbers are formed decimally, they end with a suffix that originally indicated the grammatical gender of the noun the numeral refers to.
'This suggests that, in earlier times, the suffixes of decimal numerals actually changed to reflect grammatical gender. This implies that the decimal system was not a later introduction but had been in use long enough for gender markers in decimal numerals to become fossilised,' the linguist notes.
Dialectal variations in numeral systems can sometimes occur on opposite sides of the same mountain. For example, in the northern areas where Aghul is spoken, people count by tens, while in the southern parts, they count by twenties. Sometimes both systems coexist side by side: the older generation sticks to the traditional system, younger people use the more recent one, and some numerals reflect a mix of both systems.

Such variability shows how vibrant and dynamic different elements of a language—including numerals—can be. The study suggests that numeral systems can be easily borrowed, adapted, and changed spontaneously. Their history is not simply a progression from 'primitive' to 'advanced' structures, but a complex process that deserves close study—especially in linguistically rich and diverse regions like the Caucasus.
The study was conducted with support from HSE University's Basic Research Programme within the framework of the Centres of Excellence project.
See also:
HSE Researchers Determine Frequency of Genetic Mutations in People with Pulmonary Hypertension
For the first time in Russia, a team of scientists and clinicians has conducted a large-scale genetic study of patients with pulmonary arterial hypertension. The team, which included researchers from the International Laboratory of Bioinformatics at the HSE Faculty of Computer Science, analysed the genomes of over a hundred patients and found that approximately one in ten carried pathogenic mutations in the BMPR2 gene, which is responsible for vascular growth. Three of these mutations were described for the first time. The study has been published in Respiratory Research.
HSE Scientists Reveal How Disrupted Brain Connectivity Affects Cognitive and Social Behaviour in Children with Autism
An international team of scientists, including researchers from the HSE Centre for Language and Brain, has for the first time studied the connectivity between the brain's sensorimotor and cognitive control networks in children with autism. Using fMRI data, the researchers found that connections within the cognitive control network (responsible for attention and inhibitory control) are weakened, while connections between this network and the sensorimotor network (responsible for movement and sensory processing) are, by contrast, excessively strong. These features manifest as difficulties in social interaction and behavioural regulation in children. The study has been published in Brain Imaging and Behavior.
Similar Comprehension, Different Reading: How Native Language Affects Reading in English as a Second Language
Researchers from the MECO international project, including experts from the HSE Centre for Language and Brain, have developed a tool for analysing data on English text reading by native speakers of more than 19 languages. In a large-scale experiment involving over 1,200 people, researchers recorded participants’ eye movements as they silently read the same English texts and then assessed their level of comprehension. The results showed that even when comprehension levels were the same, the reading process—such as gaze fixations, rereading, and word skipping—varied depending on the reader's native language and their English proficiency. The study has been published in Studies in Second Language Acquisition.
‘The Future Is Not Predetermined—We Shape It with the Decisions We Make Today’
The strategic technological project ‘National Centre of Science, Technology, and Socio-Economic Foresight’ at HSE University spans horizons of 10 to 30 years and involves developing new methodologies of scenario analysis. It brings together researchers from different fields and helps to form a holistic vision of the future. The aim of the project is not only to produce forecasts but also to generate practical recommendations for government and business. Anastasia Likhacheva, Dean of the HSE Faculty of World Economy and International Affairs, explains why it is important to learn to ask the right questions about the future.
Mortgage and Demography: HSE Scientists Reveal How Mortgage Debt Shapes Family Priorities
Having a mortgage increases the likelihood that a Russian family will plan to have a child within the next three years by 39 percentage points. This is the conclusion of a study by Prof. Elena Vakulenko and doctoral student Rufina Evgrafova from the HSE Faculty of Economic Sciences. The authors emphasise that this effect is most pronounced among women, people under 36, and those without children. The study findings have been published in Voprosy Ekonomiki.
Scientists Discover How Correlated Disorder Boosts Superconductivity
Superconductivity is a unique state of matter in which electric current flows without any energy loss. In materials with defects, it typically emerges at very low temperatures and develops in several stages. An international team of scientists, including physicists from HSE MIEM, has demonstrated that when defects within a material are arranged in a specific pattern rather than randomly, superconductivity can occur at a higher temperature and extend throughout the entire material. This discovery could help develop superconductors that operate without the need for extreme cooling. The study has been published in Physical Review B.
Scientists Develop New Method to Detect Motor Disorders Using 3D Objects
Researchers at HSE University have developed a new methodological approach to studying motor planning and execution. By using 3D-printed objects and an infrared tracking system, they demonstrated that the brain initiates the planning process even before movement begins. This approach may eventually aid in the assessment and treatment of patients with neurodegenerative diseases such as Parkinson’s. The paper has been published in Frontiers in Human Neuroscience.
Civic Identity Helps Russians Maintain Mental Health During Sanctions
Researchers at HSE University have found that identifying with one’s country can support psychological coping during difficult times, particularly when individuals reframe the situation or draw on spiritual and cultural values. Reframing in particular can help alleviate symptoms of depression. The study has been published in Journal of Community Psychology.
HSE University–St Petersburg Holds Summer Intensive Course on Finance for Students from Five Countries
The International Summer School at HSE University–St Petersburg included the intensive course 'New Economic Drivers for Company.' International students explored the realm of applied finance through case studies of Russian companies.
Scientists Clarify How the Brain Memorises and Recalls Information
An international team, including scientists from HSE University, has demonstrated for the first time that the anterior and posterior portions of the human hippocampus have distinct roles in associative memory. Using stereo-EEG recordings, the researchers found that the rostral (anterior) portion of the human hippocampus is activated during encoding and object recognition, while the caudal (posterior) portion is involved in associative recall, restoring connections between the object and its context. These findings contribute to our understanding of the structure of human memory and may inform clinical practice. A paper with the study findings has been published in Frontiers in Human Neuroscience.