Fact Check: Are bonobos aggressive?

Are Bonobos Aggressive?

The claim that bonobos, often referred to as the "peaceful apes," may exhibit aggressive behaviors has been the subject of recent studies. Historically, bonobos have been characterized by their relatively peaceful social structures compared to their close relatives, chimpanzees. However, new research suggests that the reality may be more complex, indicating that male bonobos can be quite aggressive, particularly towards other males. This article will explore the evidence surrounding this claim, presenting a balanced view of the findings and the reliability of the sources.

What We Know

1. Aggression Rates: A study published in Current Biology found that male bonobos engage in aggressive behaviors at a rate 2.8 times higher than male chimpanzees, contradicting the long-held belief that bonobos are predominantly peaceful 48. This study involved extensive observation, totaling 9,300 hours, and focused on 12 male bonobos and 14 male chimpanzees.

2. Female Strategies: Research highlighted in AP News and NBC News indicates that female bonobos form coalitions to fend off male aggression, suggesting a social strategy to mitigate potential threats from males 210. This behavior is seen as a response to the males' aggression, with females often banding together to assert their dominance in social interactions.

3. Comparative Aggression: While bonobos exhibit lower rates of male-female aggression compared to chimpanzees, they show higher rates of female-male aggression 1. This nuanced understanding of aggression patterns is critical in evaluating the social dynamics of bonobos.

4. Previous Studies: Earlier research indicated that severe male aggression, particularly lethal aggression, is prevalent in chimpanzees but largely absent in bonobos 6. This historical context is essential for understanding the evolution of perceptions about bonobo behavior.

Analysis

The evidence surrounding bonobo aggression presents a complex picture. The study conducted by the researchers, which claims that bonobos are more aggressive than previously thought, is based on a substantial amount of observational data, lending it credibility 4. However, it is important to consider the potential biases in how aggression is defined and measured. For instance, the study focuses on physical aggression, which may not encompass all forms of aggressive behavior, such as social or psychological aggression.

The sources reporting on these findings vary in their reliability. For example, The New York Times and National Geographic are reputable outlets known for their scientific reporting, but they may also have editorial biases that influence how they present findings 45. In contrast, ScienceDaily often summarizes research findings and may lack the depth of analysis found in peer-reviewed journals 7.

Moreover, the framing of bonobos as "hippie chimps" in some articles may reflect a sensationalized narrative that could skew public perception. This characterization could lead to confirmation bias, where readers may selectively interpret new findings to fit preconceived notions about bonobos' nature.

The studies also raise questions about the methodology used to observe and categorize aggressive behaviors. While the observational approach is robust, the interpretation of what constitutes aggression can vary significantly among researchers. Additional longitudinal studies that explore the context of aggressive interactions could provide a more comprehensive understanding of bonobo behavior.

Conclusion

Verdict: Partially True

The claim that bonobos exhibit aggressive behaviors is partially true. Evidence from recent studies indicates that male bonobos can indeed be aggressive, particularly towards other males, which challenges the traditional view of bonobos as entirely peaceful. Notably, a study found that male bonobos engage in aggressive behaviors at a rate significantly higher than that of male chimpanzees, suggesting a more complex social dynamic than previously understood.

However, it is essential to recognize that while bonobos show higher rates of aggression in certain contexts, they also exhibit lower rates of male-female aggression compared to chimpanzees. This nuanced understanding highlights the variability in aggression patterns among bonobos. The framing of bonobos as "peaceful" or "aggressive" may oversimplify their behavior, and the definition of aggression itself can vary among researchers, which introduces further complexity.

Limitations in the available evidence include potential biases in observational studies and the need for more comprehensive research that considers different forms of aggression beyond physical confrontations. As such, while the assertion that bonobos can be aggressive is supported by evidence, it is not an absolute characterization of their behavior.

Readers are encouraged to critically evaluate information and consider the broader context when interpreting claims about animal behavior, as simplifications can lead to misunderstandings.

Sources

1. Mouginot, M. (2024). Differences in expression of male aggression between wild bonobos and chimpanzees. PubMed. Link
2. AP News. (2025). Bonobos in Congo form girl groups to fend off male aggression, study. Link
3. Science. (2024). Bonobos, the 'hippie chimps,' might not be so mellow after all. Link
4. The New York Times. (2024). No 'Hippie Ape': Bonobos Are Often Aggressive, Study Finds. Link
5. National Geographic. (2024). Peace-loving bonobos are more aggressive than we thought. Link
6. Cell. (2024). Differences in expression of male aggression between wild bonobos and chimpanzees. Link
7. ScienceDaily. (2024). Bonobos are more aggressive than previously thought, study. Link
8. Smithsonian Magazine. (2024). Male Bonobos, Close Human Relatives Long Thought to Be Peaceful, Are Actually Quite Aggressive, Study Suggests. Link
9. ScienceDaily. (2025). Female bonobos keep males in check. Link
10. NBC News. (2025). Bonobos form girl groups to fend off male aggression, study says. Link