Reacción a "Two macaques can tap to the beat of music in an experimental study"

For decades, certain cognitive abilities were thought to be unique to humans. The use of tools, for example, was considered a strictly human trait until Jane Goodall observed how chimpanzees in Gombe used twigs to extract termites, demonstrating that they were capable of making and using tools in their search for food (Goodall, 1964).

Culture also ceased to be considered an exclusively human phenomenon when the macaques on Koshima Island surprised the world: a young female began washing sweet potatoes in the river, and this behavioural innovation was imitated by other members of the group, thus documenting a clear case of non-human cultural transmission (Kawai, 1965).

Recently, studies with great apes have questioned another ability that was long considered exclusively human: theory of mind, understood as the ability to attribute to others beliefs, knowledge or intentions different from one's own. Research such as that by Krupenye et al. (2016) has shown that these animals can anticipate the behaviour of others based on false beliefs, a manifestation compatible with incipient forms of theory of mind.

Now, this study, published in Science (Rajendran et al., 2025), adds another piece to this puzzle: musical rhythm. The authors have shown that macaques can detect, anticipate and synchronise with the rhythm of real music, a behaviour that until now was believed to be unique to humans and a few species with complex vocal abilities, such as certain songbirds.

In a series of three experiments, the macaques not only learned to keep time by tapping in sync, but also chose to do so spontaneously, even when it was not necessary to receive a reward. This ability suggests that rhythmic synchronisation is not an “all or nothing” property, but can emerge gradually if certain basic cognitive processes are coordinated.

This finding gives rise to a new theoretical proposal: the 4-component hypothesis (4Cs). According to this hypothesis, any species that can (1) detect auditory patterns, (2) make temporal predictions, (3) coordinate motor actions with those patterns, and (4) associate that behaviour with a reward, could develop some degree of rhythmic musical perception. It is a more inclusive approach than the previous model, based exclusively on vocal learning, and allows for continuity between species.

The authors clarify that this does not mean that macaques experience music in the same way as humans. Unlike humans, who display this ability naturally from childhood, macaques required extensive training and found the task demanding. The motivation to synchronise does not appear to be intrinsic, but rather conditioned by the reward system. Even so, once trained, the macaques generalised the skill to new songs, suggesting the activation of cognitive mechanisms comparable to those of humans.

Overall, this study not only challenges our ideas about animal musicality, but also reinforces a more gradual and evolutionary view of complex cognition. As with tool use, culture and theory of mind, rhythm is no longer a strictly human frontier. The line that separates us from other species with complex cognitive abilities is becoming increasingly blurred, reminding us that we share a common past and also some of the abilities that we believed to be exclusively ours.