Sibling rivalry among baboons

[Press release] - Published on February 19, 2026 in Press Room, Science-Society

A new study conducted by the University of Montpellier and the Montpellier Institute of Evolutionary Sciences (ISEM), in collaboration with the CNRS, sheds new light on the emotional lives of primates. Published in the scientific journal Proceedings of the Royal Society B, this research shows that young baboons exhibit behaviors similar to jealousy when they observe their mother caring for a brother or sister. Conducted in their natural environment, this research opens up new perspectives for understanding the evolution of social emotions in animals.

A groundbreaking study on jealousy in nature

Jealousy is a complex social emotion that arises when an individual perceives their relationship with a social partner to be threatened by a third party. While its existence in non-human animals is still debated, it had never before been studied directly in the wild.

To answer this question, an international team led by scientists from the University of Montpellier (ISEM) and the CNRS looked at a situation that is well known in humans: sibling rivalry for maternal attention. The researchers observed grooming interactions between baboon mothers and their young, analyzing the reactions of other siblings.

The results show that young baboons frequently intervene when their mother is grooming a sibling, and solicit her more in this context than when she is simply resting. These interventions do not generally allow them to obtain more care, but they sometimes interrupt the interaction in progress, suggesting an attempt to disrupt the relationship between the mother and the rival.

Behaviors comparable to human jealousy

Observations reveal that young baboons preferentially target certain members of their sibling group: younger individuals, those of the same sex, and "favorites," i.e., those who receive the most maternal care. These non-aggressive behaviors closely resemble the manifestations of jealousy observed in human children.

These results support the hypothesis that baboons are capable of experiencing forms of jealousy. They also suggest that these primates are able to assess fairness in the distribution of maternal attention.

Beyond these conclusions, this study, conducted by the University of Montpellier and the CNRS, demonstrates that it is possible to study animal emotions directly in their natural environment. It thus opens up new perspectives for better understanding the ecology, evolution, and complexity of social emotions in nonhuman primates.

A few points:

• Young baboons frequently interfere when their mother is grooming a sibling, and solicit her more in this context than when she is available.
• They preferentially target younger siblings of the same sex, as well as individuals receiving the most maternal attention;
• These behaviors bear strong similarities to the jealousy observed among human siblings, suggesting comparable emotional mechanisms.