Human communication is a complex interplay of vocal signals, gestures, facial expressions, and postures, largely influenced by early life interactions with caregivers. Until now, the extent to which these traits are culturally transmitted versus genetically inherited has been debated within primatology. Chimpanzees, sharing about 98% of our DNA, employ an equally diverse set of communicative signals, yet the origins—learned or innate—of these behaviors have remained elusive. By focusing on wild chimpanzees in Kibale National Park, Uganda, Mine’s team sought to unravel whether the nuances of their communicative styles arise through social learning or genetic predisposition.

The study monitored 22 habituated chimpanzees over significant periods, meticulously recording both vocalizations such as grunts, barks, and whimpers, alongside non-vocal cues including arm movements, gaze directions, and body postures. Using an integrative analytical approach, the researchers quantified how these signals combined within individuals. Strikingly, patterns emerged revealing that offspring shared a marked similarity in communication styles with their mothers and maternal kin, but not with fathers or paternal kin. This differential indicates that maternal influence, not paternal genetics, predominantly shapes communicative behavior.

Such findings are particularly compelling given chimpanzee social structure, where maternal care is intensive and prolonged, whereas paternal involvement in offspring rearing is minimal or absent. Thus, the transmission of communication style aligns more with social exposure and learning opportunities than strict genetic inheritance. The offspring appear to internalize and replicate the multimodal communication behaviors exhibited by their mothers, highlighting the vital role of maternal interaction in the developmental trajectory of communicative competence.

Importantly, all observed individuals were older than ten years—an age marking increasing independence from their mothers—signaling that maternally derived communication patterns endure well beyond early childhood. This persistence suggests that social learning mechanisms engrain communication styles deeply, potentially affecting social dynamics and cohesion throughout the chimpanzee’s lifespan. Consequently, these results offer new perspectives on the evolutionary origins of communication, proposing that the capacity for social learning in vocal and visual signals is more ancient and fundamental than previously acknowledged.

In a direct statement, lead author Joseph Mine emphasized the variability observed across chimpanzee families, noting how “certain chimpanzee mothers tend to produce many vocal-visual combinations, while others produce few. And the offspring end up behaving like the mothers, resulting in family-specific tendencies.” This insight signifies the potential for diverse communication cultures within wild chimpanzee populations, shaped by nuanced maternal influence rather than rigid genetic codes.

Simon Townsend, co-author of the study, further elaborated on the sophistication of the research approach. He explained that “in humans, body language includes hand gestures and facial expressions, but also many subtle behaviours, like shifts in posture and gaze direction. With our approach, we were able to assess whether chimpanzees learn about these less salient features as well.” Such an innovative methodology underscores the intricacy of primate communication and the subtlety through which social learning guides communicative behaviors.

Katie Slocombe, another co-author, expressed enthusiasm about future directions stemming from the research, “I think it’s fascinating that mothers who produce more visual behaviours when they vocalise, raise offspring that follow suit. The next exciting step will be to see if offspring are learning certain types of visual-vocal combinations from their mothers, in addition to the number of visual behaviours they produce when they vocalise.” This prospect opens thrilling avenues into understanding how complex communicative repertoires evolve and diversify within primate societies through social transmission.

More broadly, the implications of this research extend beyond chimpanzees, offering valuable comparative insights into the evolutionary pathways that led to human language and communication. It suggests that the building blocks for culturally transmitted multimodal communication systems exist deeply embedded in primate heritage. Recognizing that social learning plays a distinct and dominant role in shaping communication encourages a reevaluation of how language may have emerged through incremental adaptations grounded in social interactions.

The study was funded through multiple esteemed sources, including the Swiss National Science Foundation, the European Research Council, and the National Science Foundation in the United States, underpinning its robust scientific foundation. It epitomizes a high-caliber international collaboration committed to advancing understanding of animal cognition and communication.

For those interested in exploring the full detailed findings, the paper is freely accessible in PLOS Biology at http://plos.io/4lsNJkO. This open access ensures that scientists, educators, and the public alike can engage with cutting-edge research illuminating the profound social complexity of chimpanzee communication.

This research represents a significant step forward in animal communication studies, revealing that the style and structure of how chimpanzees communicate are less a matter of inherited biology and more a result of dynamic social learning influenced by maternal kin. These revelations not only enrich primatology but also deepen our appreciation for the shared roots of social behavior and communication in the animal kingdom.

Subject of Research: Animals

Article Title: Chimpanzee mothers, but not fathers, influence offspring vocal–visual communicative behavior

News Publication Date: August 5, 2025

Web References:

• Full paper: http://plos.io/4lsNJkO
• DOI: http://dx.doi.org/10.1371/journal.pbio.3003270

References:
Mine JG, Dees LC, Wilke C, Willems EP, Machanda ZP, Muller MN, et al. (2025) Chimpanzee mothers, but not fathers, influence offspring vocal–visual communicative behavior. PLoS Biol 23(8): e3003270.

Image Credits: Ray Donovan (CC-BY 4.0)

Keywords: Chimpanzee communication, social learning, vocal-visual signals, primate behavior, maternal influence, multimodal communication, animal cognition, evolutionary biology

Chimpanzees, members of the great ape family sharing close genetic ties with humans, have long been observed using medicinal plants for self-treatment. However, Dr. Freymann’s study, published in Frontiers in Ecology and Evolution, meticulously documents instances of both self-directed care and prosocial medical intervention in two chimpanzee communities known as Sonso and Waibira within Budongo Forest. What stands out is the persistence and complexity of such behaviors which go beyond immediate familial bonds, signifying sophisticated social cognition and an inherent recognition of suffering within the community.

The study is grounded in extensive field observations over several months, alongside analysis of decades-old video archives and consultations with primatologists worldwide. Each recorded intervention reveals a nuanced application of natural pharmacology. Chimpanzees were found to employ a repertoire of wound-care techniques including direct licking, which likely serves antimicrobial functions via saliva enzymes, as well as the use of chewed plant materials known to contain bioactive compounds conducive to tissue regeneration and infection control.

Not only do these chimpanzees display self-care by treating their own injuries, but crucially, they also engage in prosocial care—actions intended to aid others. This includes removing snares, assisting with wound treatment, and even hygiene activities such as cleaning genitals and anogenital areas with leaves following mating or defecation events. These behaviors likely lower infection risks, underscoring an evolved behavioral complexity that mirrors some facets of human medical care.

Quantitative data from the Budongo communities revealed 41 documented instances of healing behaviors, split between seven prosocial acts and 34 acts of self-care. Remarkably, the prosocial interventions were neither biased by kinship nor sex or age class, indicating a communal sense of welfare extending beyond genetically close individuals. The researchers suggest that social hierarchy stability, habituation levels of chimpanzee groups, and possibly ecological factors such as high injury risk from human snares influence the prevalence and visibility of these behaviors.

From an evolutionary biology perspective, these findings provide an unprecedented window into the precursors of human medicine. The chimpanzees’ selective use of medicinal plants and the deliberate multi-step wound care processes hint at cognitive capabilities involving problem-solving, memory, and social learning. These capacities would have been crucial in early hominin societies grappling with frequent injuries and the associated threats of infection and morbidity.

The researchers also noted that healing behaviors varied within and between communities, which may reflect cultural traditions or environmental constraints shaping healthcare strategies. Sonso chimpanzees exhibited more frequent prosocial medical actions, possibly linked to their longer habituation to human observers and higher social stability, making these behaviors easier to document. In contrast, the Waibira group’s lower visibility offers a reminder of methodological challenges in field primatology, especially when studying rare or subtle social behaviors.

One intriguing aspect of the study was the detailed description of wound-care techniques. Chimpanzees used leaf-dabbing to absorb pus or blood, finger licking combined with pressing of wounds to remove contaminants, and applications of plant compounds that could serve antiseptic and anti-inflammatory roles. The recorded recovery of injured chimpanzees supports the efficacy of these behaviors, although controlled pharmacological testing is pending to confirm the biochemical pathways involved.

Hygiene-related care further underscores the complexity of chimpanzee health management. The use of leaves to clean genitals after mating and anal areas after defecation reflects behavioral adaptations to reduce bacterial loads and subsequent infections. This nuanced attention to cleanliness is a foundational aspect of disease prevention, often overlooked in discussions of animal care but essential for understanding the trajectory of human healthcare evolution.

While the study’s findings are groundbreaking, Dr. Freymann and her colleagues highlight important limitations. Observation bias due to uneven habituation levels between communities and the rarity of prosocial care events impose constraints on interpreting the prevalence and drivers of healthcare behaviors. Moreover, the research calls for integrated pharmacological analyses to validate the specific medicinal properties of plants used, an essential step for bridging behavioral ecology with biochemical medicine.

Arguably, one of the most profound implications of this research lies in the social motivations underpinning chimpanzee care. The documented instances, including help given to unrelated individuals, suggest an empathetic recognition of distress and an evolved prosocial disposition. Such motivations could have been the evolutionary bedrock upon which human altruistic healthcare systems were constructed, reinforcing social cohesion and group survival.

Looking forward, this work opens exciting avenues for interdisciplinary study, merging primatology, ethnobotany, pharmacology, and evolutionary psychology. The urgent need for deeper investigation into social contexts, individual care roles, and ecological pressures promises richer understanding of how natural history shaped the emergence of medicine. It also offers valuable lessons for conservation efforts, emphasizing the importance of preserving not only species but the cultural and behavioral diversity within animal communities.

In unraveling the medical behaviors of Budongo’s chimpanzees, Dr. Freymann’s research eloquently bridges the chasm between human and nonhuman healthcare practices. It illuminates a shared evolutionary heritage where compassion, cognition, and the application of natural resources converge to address suffering. As humanity continues to confront health challenges, reflecting on these ancestral roots reminds us that caregiving is not solely a human invention but part of a broader biological continuum.

Subject of Research: Animals

Article Title: Self-Directed and Prosocial Wound Care, Snare Removal, and Hygiene Behaviors Amongst the Budongo Chimpanzees

News Publication Date: 14-May-2025

Web References: 10.3389/fevo.2025.1540922

Image Credits: Dr. Elodie Freymann

Bonobo societies are primarily characterized by their matriarchal tendencies, which manifest in unusual ways for a species where sexual dimorphism favors males. Conventionally, stronger, larger males dominate social hierarchies and secure preferential access to both mating opportunities and resources. However, in bonobo groups studied across the Democratic Republic of Congo—the species’ sole natural habitat—females break this typical mold. The research combined three decades of meticulous observations from six distinct bonobo communities, unveiling a rare social structure where female alliances systematically counterbalance male dominance. This aligns with longstanding, yet under-tested, hypotheses suggesting that female cooperation is central to understanding their elevated social status.

The key finding emerging from the longitudinal dataset of nearly 1,800 recorded conflicts between sexes was that females frequently formed coalitions—strategic social “gangs”—to collectively subdue males during contests. These coalitions overwhelmingly target males, forcing them into submission and actively reshaping dominance hierarchies. Notably, 85% of the observed coalitions involved female-female alliances directing aggression or intimidation towards males. By banding together, females could neutralize individual physical disadvantages, engineering an inversion of the expected male-biased power structure prevalent in most mammals. This behavioral adaptation offers new insights into the evolutionary pressures that may favor social bonding and strategic cooperation over brute strength.

Delving deeper into the behavioral ecology, the study reveals that female bonobos’ reproductive strategies intertwine intricately with their dominance tactics. Unlike many primate species where male monopolization of female reproductive cycles is common, bonobos exhibit concealed ovulation and reproductive autonomy. These factors hinder males’ ability to predict optimal mating times and enforce monopolies, thus reducing the incentive for coercive behaviors. Females thus maintain selective control over mating decisions, further amplifying their leverage in social interactions. The synergy between reproductive strategy and coalition formation emerges as a cornerstone of female empowerment, suggesting that evolution has favored nuanced social intelligence and alliance-building in bonobo females.

The formation of these coalitions is marked by intense, rapid escalation within moments of conflict, frequently evidenced by loud, piercing female vocalizations described as deafening by researchers. These vocal displays precede coordinated pursuits where females collectively harass target males through the dense forest canopy, at times inflicting severe or even fatal injuries. The ferocity and cohesion of these groups intimidate males and establish clear social boundaries, effectively regulating male behavior without relying solely on direct physical dominance. Such vocal and cooperative tactics reveal complex communication and social organization, underscoring the cognitive sophistication underlying bonobo societies.

Despite these compelling dynamics, the nature of female dominance in bonobos is far from absolute or uniform across all populations. The study highlights considerable variation, with females winning approximately 61% of observed conflicts on average and outranking 70% of males. However, these figures represent a spectrum of dominance rather than consistent, unchallenged rule. This suggests that female power is context-dependent and modulated by local ecological and social conditions. Far from presenting a monolithic matriarchy, bonobo societies reflect flexible, negotiated power relations where female high status is maintained through both alliances and reproductive strategies, but is periodically contested.

The implications of this research extend beyond primatology, challenging entrenched narratives about sex, power, and social hierarchy in mammals and, by extension, in evolutionary studies of humans. The demonstration that female social solidarity can invert typical male-dominated structures invites fresh perspectives on how cooperation among females might have shaped social evolution in our own lineage. It underscores the possibility that strategic alliance-building, rather than brute dominance alone, has been a critical driver in the emergence of complex social systems, particularly among species closest to humans.

Furthermore, the study’s methodology—compiling a vast longitudinal dataset from multiple wild populations and conducting rigorous statistical analyses of conflict outcomes—adds robust empirical weight to previously speculative explanations. By quantifying conflict patterns and linking them to social bonds and demographic variables, the researchers have pioneered a model for studying power dynamics in non-human animals that integrates behavioral ecology with sociobiology. This approach not only clarifies bonobo social organization but sets a precedent for multifaceted investigations of dominance and cooperation.

Intriguingly, many females involved in coalitions are unrelated immigrants to their groups, a fact that intensifies the unexpected nature of these bonds. Unlike kin-based alliances common in many species, this cooperation forms between strangers, highlighting the role of social learning, trust, and reciprocal behavior in constructing power networks. The rapid formation of coalitions during conflicts suggests that bonobo females possess remarkable social agility, enabling them to mobilize support swiftly in response to threats or challenges, a trait critical for survival in their complex jungle environment.

The researchers emphasize that female coalition formation is but one mechanism underpinning female empowerment among bonobos. Reproductive autonomy and concealed ovulation likely complement coalitionary behaviors by reducing male aggression and promoting social stability. Future investigations are poised to explore these interactions further, examining how fertility cues, mating patterns, and hormonal cycles influence female status and coalition dynamics. Such integrated studies promise a fuller understanding of the biological and social underpinnings of female power.

Despite the clarity gained, the evolutionary origins of this remarkable female solidarity remain enigmatic. The researchers acknowledge that why bonobos—out of all mammals—have evolved such cooperative female alliances remains an open question. This mystery offers fertile ground for future research into the evolutionary pressures unique to bonobo habitats and life histories that may have favored female coalition-building over traditional dominance hierarchies. Understanding these drivers may illuminate parallel processes in early human social evolution.

Ultimately, this new research into bonobo social dynamics offers a powerful reminder that power and dominance are multifaceted, context-dependent phenomena. The ability of female bonobos to wield influence in a male-sized world through strategic alliances reshapes foundational theories about social organization in mammals. By revealing the delicate balance between strength, cooperation, and reproductive strategy, the study not only enriches our understanding of bonobos but also invites profound reflections on the role of female solidarity in shaping the trajectories of social species—potentially including our own.

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Subject of Research: Animals
Article Title: Drivers of Female Power in Bonobos
News Publication Date: 24-Apr-2025
Web References: http://dx.doi.org/10.1038/s42003-025-07900-8
Image Credits: Melodie Kreyer / LKBP
Keywords: Bonobo social structure, female coalition, primate dominance hierarchy, reproductive autonomy, animal behavior, evolutionary biology, social bonds, sexual dimorphism, coalition formation, female empowerment, conflict resolution, behavioral ecology