# Aleksandar Tomašević, Associate Research Professor I'm an Associate Research Professor at the [Scientific Computing Laboratory](https://www.scl.rs/) of the [Institute of Physics Belgrade](https://www.ipb.ac.rs/). I study online communities as complex social systems, combining behavioral data, network analysis, machine learning, and simulation. My current work focuses on LLM-agent simulations of online platforms, community sustainability, trust and reputation processes, political communication, populism, and AI-mediated social dynamics. I also build open-source tools for analyzing emotion in text, images, and video. I earned my PhD at the University of Novi Sad in 2019, working on quantitative methods and network science. I was a [Fulbright Scholar](https://fulbrightscholars.org/grantee/aleksandar-tomasevic) at the University of Virginia in 2023–2024, an invited speaker at the [International Meeting of the Psychometric Society](https://www.psychometricsociety.org/invited-speaker/aleksandar-tomasevic-university-novi-sad-serbia), and one of the developers of [YSocial](https://y-not.social/about). I am an Editorial Board Member at [BMC Psychology](https://link.springer.com/journal/40359/editorial-board) and an Academic Editor at [PLOS One](https://journals.plos.org/plosone/). I serve as an ad hoc reviewer for a multitude of scientific journals, such as *Personality and Individual Differences*, *Scientific Reports*, *Humanities and Social Sciences Communications*, *EPJ Data Science*, *Computational Communication Research*, *Quality & Quantity*, and *Acta Psychologica*. Erdős number 4: Paul Erdős → Béla Bollobás → Guido Caldarelli → Marija Mitrović Dankulov → Aleksandar Tomašević.  ## News & Updates ### 2026 - Preprint [“Oh No, the Robots Are Here”: AI identity labels, social uptake and sanctioning in mixed human–AI communities](https://osf.io/preprints/psyarxiv/kwy5j_v2) on PsyArXiv. The experiment data are on [Zenodo](https://doi.org/10.5281/zenodo.22964196). - A case was accepted for *Sage Research Methods: Using AI for Research*. - Accepted oral presentation at [Complex Networks 2026](https://complexnetworks.org/) (Granada, 2–4 December): “Structural Dynamics of Online Social Networks: From Empirical Cohort Mixing to Generative Network Models.” - Livestream seminar with Hudson Golino, [AI-Based Emotion Analysis for Text, Image, and Video](https://stathorizons.eventsmart.com/events/ai-based-emotion-analysis-for-text-image-and-video-november-2026/), Statistical Horizons, 4, 6, and 7 November 2026. - Editorial Board Member at [BMC Psychology](https://link.springer.com/journal/40359/editorial-board). - The latent oscillator measurement model paper is on arXiv: [A Latent Oscillator Measurement Model to Simulate Emotional-Expression Score Dynamics in Video](https://arxiv.org/abs/2609.15273) ([PsyArXiv](https://doi.org/10.31234/osf.io/hf3g7)). - Paper on Reddit deplatforming and cohort mixing in generalist Voat communities published in [Scientific Reports](https://doi.org/10.1038/s41598-026-63627-4) ([arXiv preprint](https://arxiv.org/abs/2512.22348)). - The dynEGA case-study paper was published in [Psychiatry Research Case Reports](https://doi.org/10.1016/j.psycr.2026.100342) ([OSF preprint](https://doi.org/10.31234/osf.io/urfek_v1)). - Our paper, “Between ‘we’ and ‘well-being’: Do basic psychological needs mediate the relationship between interdependent self-construal and adolescent subjective well-being?”, was published in [Applied Psychology: Health and Well-Being](https://doi.org/10.1111/aphw.70172) ([OSF preprint](https://osf.io/preprints/osf/r4vfp_v1)). - Served on the examination committee for the Italian National PhD Programme in Artificial Intelligence, AI for Society track, at CNR Pisa. - Invited seminar at ISTI-CNR in Pisa: “From Simulated Online Communities to Hybrid Publics with YSocial: Operational Validation and Experimental Evidence” ([official event](https://www.isti.cnr.it/announcements/seminars/17/From_Simulated_Online_Communities_to_Hybrid_Publics_with_YSocial%3A_Operational_Validation_and_Experimental_Evidence), [slides](https://docs.google.com/presentation/d/1UZQJa1CSCb9o3Cb5v5VEF0Pl7_5ARJOrAs4QVjtArZw/view?usp=sharing)). - Our work “From Agents to Humans: Network Structure and Homophily in LLM-Simulated and Mixed Online Communities” was presented by Sara Major at [Sunbelt 2026](https://www.insna.org/events/sunbelt-2026---daytona-beach). - YSocial operational validation paper published in [EPJ Data Science](https://doi.org/10.1140/epjds/s13688-026-00674-x). - Paper on analytical robustness in the social and behavioural sciences published in [Nature](https://doi.org/10.1038/s41586-025-09844-9). - Paper on personal, relational, public, and collective identity orientations published in [Identity](https://doi.org/10.1080/15283488.2026.2649028). - Paper on depression and anxiety symptoms in adolescents across 30 countries in [Journal of Affective Disorders](https://doi.org/10.1016/j.jad.2026.121693). - Paper on AI-based student feedback analysis in [College Teaching](https://doi.org/10.1080/87567555.2026.2639369). - Paper on `transforEmotion` published in [Computational Communication Research](https://www.aup-online.com/content/journals/10.5117/CCR2026.2.2.TOMA). - Talk on "transforEmotion: Multimodal Emotion Analysis in R" at [IAAP Webinar: AI & Emotion in Digital Life](https://atomasevic.xyz/talks/IAAP.html). - Talk on "transforEmotion in Practice: Multimodal Emotion Analysis in R" at [Vanderbilt University QMDA Colloquium](https://www.vanderbilt.edu/psychological_sciences/graduate/programs/quantitative-methods/colloquium.php). ### 2025 - Preprint [Reddit Deplatforming and Toxicity Dynamics on Generalist Voat Communities](https://arxiv.org/abs/2512.22348) on arXiv. - Preprint [Towards Operational Validation of LLM-Agent Social Simulations: A Replicated Study of a Reddit-like Technology Forum](https://arxiv.org/abs/2508.21740) on arXiv. - Paper on cross-national invariance of externalizing problems screener in [Development and Psychopathology](https://doi.org/10.1017/S0954579425100473). - Paper on positive and negative emotional experiences in adolescents across 32 countries in [Applied Research in Quality of Life](https://doi.org/10.1007/s11482-025-10486-2). - Paper on understanding democracy in Europe in [Sociologija](https://doi.org/10.2298/SOC2502171T). [See all updates →](https://atomasevic.xyz/updates.html)