For decades, animal personality research has operated under the assumption that individual creatures demonstrate consistent and measurable behaviours over time. These behavioural consistencies—often categorized as “bold,” “shy,” or “aggressive”—have provided valuable insights into how animals interact, survive, and evolve. However, new research on African social spiders, specifically the species Stegodyphus dumicola, colloquially known as “hippie spiders” due to their cooperative and egalitarian colonies, is turning this paradigm on its head. Led by researchers at the University of Portsmouth, this groundbreaking study reveals that these spiders do not conform to the traditional concept of personality. Instead, their behaviours fluctuate dramatically over time, influenced by environmental factors and internal states, which calls into question long-held assumptions in behavioural ecology.
At the core of this research lies the intriguing notion of animal personality. Conventionally, personality in animals is defined by stable behavioural traits that persist regardless of the context or passage of time. Such traits are thought to influence survival strategies and social dynamics. Yet, the meticulous observations of Stegodyphus dumicola colonies indicate a more fluid behavioural landscape. The spiders’ actions are not rigidly fixed but appear to be dynamically modulated in response to changing conditions such as hunger levels, colony needs, or external stressors. This fluidity suggests that earlier research methods, which largely relied on short-term behavioural assessments, may have oversimplified the complex behavioural repertoire of these social arachnids.
The study involved longitudinal observation of 28 separate spider colonies, each monitored biweekly over a span of four months. The researchers focused their measurements on three critical behavioural traits: boldness when confronted with threats, the speed at which an individual fled from danger, and the collective efficiency shown during prey capture. These metrics allowed scientists to quantify behavioural consistency over time and assess whether individuals maintained distinct roles within their social groups. Initial observations mirrored previous findings—spiders exhibited repeatable behaviours when monitored over short periods. However, the long-term data revealed a striking variability that defied simple categorization.
Notably, one of the most startling aspects of the findings was the lack of predictability in individual spider behaviour across their lifespan. An individual’s early behavioural tendencies had little bearing on how it acted weeks or months later. This instability challenges the idea that spider colonies function through a constellation of fixed personalities, similar to the caste systems observed in more extensively studied social insects like ants and bees. The implications extend beyond arachnology, as they prompt a reevaluation of how personality traits are defined and measured across social animals more broadly.
The lead researcher, Dr. Lena Grinsted, explains that the apparent behavioural plasticity of these spiders suggests a novel form of social organisation. Rather than discrete roles such as “forager,” “sentinel,” or “babysitter,” individuals seem to adopt tasks in a more flexible, need-based manner. This trait likely enhances the resilience and adaptability of the colony, allowing it to respond to fluctuating environmental pressures without relying on rigid behavioural specialization. In this sense, Stegodyphus dumicola exemplifies an egalitarian society where cooperation is fluid and task-sharing is dynamic, rather than hierarchically or role-structured.
The study also underscores a critical flaw in many previous personality assessments: the tendency to base conclusions on limited temporal snapshots. Behavioural ecology has long grappled with balancing practical constraints—such as time and resource restrictions—with the necessity of longitudinal data. This research demonstrates that short-term assessments may paint an incomplete or misleading picture, especially in species with fluid behavioural patterns. The authors call for a reassessment of the methodological rigor in personality research, advocating for extended monitoring periods and multifaceted behavioural measurements to capture true behavioural dynamics.
Furthermore, the findings introduce a compelling new dimension to evolutionary biology. Classical evolutionary theories often assume that individual behavioural types become fixed due to natural selection, thus driving ecological outcomes within populations. However, if behavioural traits in a species like Stegodyphus dumicola are highly plastic and context-dependent, then the evolutionary narrative must incorporate mechanisms maintaining such plasticity. This could mean that flexibility itself confers a selective advantage, helping colonies navigate unpredictable environments more effectively than fixed behavioural schemas would allow.
Another striking element is the cooperative nature of these social spiders, which contrasts with the more individualistic personality traits assumed in many species. The research highlights that cooperation, sacrifice, and collective brood care occur without apparent behavioural stratification. This contrasts sharply with social insects, where divisions of labour are often underpinned by consistent behavioural phenotypes. In hippie spider colonies, cooperation is, perhaps, a manifestation of behavioural fluidity rather than a product of personality-linked task specialization.
In practical terms, this research has notable implications for biodiversity conservation and species management. Understanding that behavioural traits are not static but highly responsive may influence how scientists predict species resilience in changing habitats and under environmental stress. For instance, management strategies relying on assumptions of fixed behavioural types might overlook critical subtleties in animal responses to habitat disturbance or climate change.
The findings also invite a broader reflection on the risks of anthropomorphizing animal behaviour—assigning human-like personality labels that do not adequately capture the complexity of life forms outside our experience. The study’s colourful conclusion that “you can’t judge a spider on first impressions” humorously yet pointedly reminds researchers to avoid simplistic classifications. It encourages an appreciation of behaviour as a dynamic and contextually adaptive trait, potentially varying not just between individuals but within the same individual over time.
The interdisciplinary nature of this research is noteworthy. It represents a collaborative effort among scientists from the University of Portsmouth, Aarhus University in Denmark, University of Paris-Saclay in France, and Ludwig Maximilian University (LMU) in Germany. This international team brought diverse expertise in behavioural ecology, evolutionary biology, and animal cognition to challenge conventional wisdom. Their findings, published in the prestigious journal Animal Behaviour, set a new benchmark for future studies of animal personality and social organisation.
As behavioural ecology moves forward, this study advocates for the necessity of embracing temporal complexity and context dependence in behavioural research. Stegodyphus dumicola’s apparent “loss” of personality traits might best be described as an evolutionary gain—a sophisticated mechanism for social cohesion and adaptability that invites us to reconsider what personality means in the animal kingdom. The humble hippie spider thus serves as a powerful symbol of the fluidity inherent in natural systems, reminding us that nature often defies our neat categorizations.
Subject of Research: Animals
Article Title: The spiders that lost their personalities: assessing long-term behavioural individuality in social Stegodyphus dumicola
News Publication Date: 28-Apr-2025
Web References: http://dx.doi.org/10.1016/j.anbehav.2025.123167
Image Credits: Dr Virginia Settepani
Keywords: Animal science, Animal research
