🐒 Chimpanzees captivated by crystals

At many prehistoric sites, archaeologists have discovered crystals alongside tools and human remains. These stones, some of which are nearly 800,000 years old, show no trace of functional use. Their presence therefore raises a question: why did our ancestors keep them when they did not seem to use them?

Researchers have explored this mystery by conducting a series of tests with chimpanzees. As our closest relatives, with a common ancestor millions of years old, these great apes offer a model to determine whether the attraction to crystals could date back to that distant time.



During the first experiment, a large quartz crystal, nicknamed "the monolith", and an ordinary stone of comparable size were presented to the animals. The chimpanzees quickly showed a marked interest in the quartz, which they examined from different angles. Some even took it back to their living space, revealing a certain attachment. The caretakers then had to trade the object for treats to retrieve it, as the primates were reluctant to part with it.

Another experiment involved mixing small quartz crystals with rounded pebbles. The chimpanzees distinguished them within seconds. Even when other types of minerals, such as pyrite or calcite, were added to the mix, they continued to identify and isolate them. An individual named Sandy even sorted them using her mouth, an uncommon gesture that could signal a particular form of valuation.

Observing these behaviors allowed researchers to identify two main characteristics of crystals that captivate chimpanzees: their transparency and their precise geometric shapes. In the natural environment, objects with straight edges and flat surfaces are unusual, whereas curved shapes dominate. Crystals are therefore a visual exception that draws attention. This particularity could also explain why prehistoric humans noticed and collected them.


This shared attraction indicates that interest in crystals might stem from a common ancestor. It would therefore not be solely a specifically human cultural behavior, but rather a visual preference deeply rooted in our evolutionary history. According to the study published in Frontiers in Psychology, this discovery reveals new aspects about the origins of aesthetics and our perception.

The study, however, has some limitations, notably the fact that the observed chimpanzees live in captivity and are accustomed to humans. Scientists plan to repeat these experiments with wild groups to confirm these observations. Furthermore, individual differences among the animals could modulate their level of interest, which requires additional research.

The geometry of crystals in nature

Crystal formation follows geological processes that produce structures with flat faces and defined angles. This geometric regularity offers a striking contrast with the organic and curved shapes that predominate in the natural landscape, such as those of plants or terrain. This visual difference makes them immediately noticeable.

Due to this rarity, objects with angular contours and smooth surfaces naturally attract attention. For living beings, detecting what stands out from the ordinary can provide an advantage, whether to identify new resources or singular elements in their environment. Crystals, with their distinctive appearance, easily stand out.

Ancient humans, like chimpanzees, were probably sensitive to these characteristics. The transparency of some crystals, which allows light to pass through, adds a visual dimension likely to pique curiosity. This combination of regular shape and clarity creates an object that intrigues and invites examination.

This attraction to geometric shapes and transparency may have played a role in the artistic and symbolic development of early human societies. Due to their uniqueness, crystals were probably perceived as special objects, worthy of being collected or integrated into emerging cultural practices.