We present a comprehensive analysis of the rise of fictions across human narratives, using large-scale datasets that collectively span over 65,000 works across various media (movies, literary works), cultures (over 30 countries, Western and non-Western), and time periods (2000 BCE to 2020 CE). We measured fictiveness – defined as the degree of departure from reality – across three narrative dimensions: protagonists, events, and settings. We used automatic annotations from large language models (LLMs) to systematically score fictiveness and ensured the robustness and validity of our measure, specifically by demonstrating predictable variations in fictiveness across different genres, in all media. Statistical analyses of the changes in fictiveness over time revealed a steady increase, culminating in the 20th and 21st centuries, across all narrative forms. Remarkably, this trend is also evident in our data spanning ancient times: fictiveness increased gradually in narratives dating back as far as 2000 BCE, with notable peaks of fictiveness during affluent periods such as the heights of the Roman Empire, the Tang Dynasty, and the European Renaissance. We explore potential psychological explanations for the rise in fictiveness, including changing audience preferences driven by ecological and social changes.

Cultural evolution of traditional music around the world has been the subject of recent quantitative investigations. Researchers have explored cultural diffusion of music as well as patterns of geographic variation that may result. By comparison, less has been studied about the process of music diversification; in particular, under what circumstances music diversifies is yet to be understood. In this study, we examine possible factors that may facilitate music diversification, using data from folk songs in the Ryukyu Archipelago, south-western islands of Japan. For a quantitative analysis, we first transform the melody of each folk song, following an automated scheme, into a sequence of alphabets, which is then used to quantify the melodic dissimilarity between each pair of songs. Our particular interest is in the dissimilarity between putative sister songs, or songs that are inferred to have derived from a common origin, and factors that have positive or negative effects on it. Our results suggest that sister songs tend to diversify more when they are sung in different islands, probably as a result of one being transmitted from one island to another, and when they have come to be sung in different social contexts.

How does information infrastructure shape long-term cultural evolution? Using over four centuries of professional game records from the game of Go, this study explores how strategic dynamics in opening moves reflect historical shifts in the ‘infostructure’ of skilled Go players. Drawing from recent work on how population size, AI, and information technology affect cultural evolution and innovation dynamics, I analyze over 118,000 games using measures of cultural diversity, divergence, and player network composition. The results show distinct eras of collective innovation and homogenization, including an early 20th-century explosion of novel opening strategies, a Cold-War-era die-off, and a recent increase in evolutionary tempo with the arrival of the internet and superhuman AI programmes like AlphaGo. Player population size shows an inverse-U relationship with opening move diversity, and a recent decline in strategic diversity has accompanied a shift in the player network, from many small subgroups to a few large ones. Surprisingly, the influence of AI has produced only a modest, short-lived disruption in the distribution of opening moves, suggesting convergence between humans and AI and incremental rather than revolutionary cultural change.

Arcade video games evolved in a constrained design space, following patterns of diversification, stabilisation, and collapse that mirror macroevolutionary processes. Despite their historical significance and detailed digital records, arcade games remain underexplored in cultural evolution research. Drawing on a dataset of 7,205 machines spanning four decades, we reconstruct the evolutionary trajectories of arcade niches using a multi-scale framework that integrates trait-level innovation, genre-level selection, and systemic constraints. We identify two contrasting dynamics: (1) resilient genres—such as Fighter and Driving—maintained long-term viability through innovation and collaboration networks, while (2) early Maze and Shooter subgenres collapsed due to imitation and weak collaboration. Morphospace analysis reveals how technological traits—specifically CPU speed and ROM size—co-evolved with gameplay complexity, shaping the viable design space. We argue that genres operated as evolving cultural-ecological units—structured niches that shaped trait evolution through reinforcement, constraint, and feedback. This multi-scale perspective positions arcade games as a rich model system for studying cultural macroevolution.

In Africa, harps exhibit significant morphological diversity, yet their historical trajectory remains largely underexplored. Phylogenetic reconstruction methods offer valuable tools for understanding this diversity and the relationships between groups of harps. This study is among the first to apply one of these methods, cladistics, to the morphology of a musical instrument, analysing 318 harps and 83 characters. We present a well-resolved phylogenetic tree, which shows several clades corresponding to geocultural regions, in alignment with ethnomusicological classifications. We show that this tree robustly represents the patterns of vertical transmission in the cultural evolution of harp morphology across Africa, despite the limited contribution of several tested characters. Additionally, a comparison with previous research reveals that characters coding decorations exert a minimal influence on the vertical evolution of these musical instruments. These findings provide valuable insights into the cultural evolution of harps on a continental scale, offering a clearer understanding of their diversity and revealing major evolutionary mechanisms.

Despite growing consensus that cognitive differences between Neanderthals and modern humans were not as significant as once assumed, visual art remains disproportionately associated with Homo sapiens. This paper explores why that is. Rather than appealing to underlying cognition, we argue that early art was pushed and pulled by social dynamics and demographic contexts on a larger scale and eventually formed through cultural transmission. Drawing on the archaeological record, we focus on pigment use, ornamentation, engravings and painting. We suggest that these practices initially remained ad hoc while still functioning as tools for social signalling and intergroup communication in the small-scale communities of Neanderthals and early modern humans. We argue that visual art moved beyond ad hoc practices under conditions of increased population density and interaction – first via the crystallization of art as a tradition and second, as cumulative cultural art. Lack of cognitive ability is not a well-supported explanation for the empirical low frequency of Neanderthal art. Instead, we propose effects of differences in social connectivity and population densities as an alternative. By reframing art as a flexible, context-dependent behaviour, we challenge essentialist models and advocate for a pluralistic view of cognitive and cultural expression across different hominin groups.