Summary: Chimpanzees continue to refine their tool-use skills well into adulthood, much like humans.
By observing 70 wild chimpanzees at Taï National Park, researchers found that while basic motor skills for using sticks as tools are acquired by age six, more complex techniques develop continuously over time, fully maturing around age 15.
This prolonged learning phase supports the idea that the capacity for lifelong learning is crucial for the evolution of complex tool use, offering insights into both chimpanzee and human cognitive development.
Key Facts:
- Continued Skill Development: Chimpanzees enhance their tool-use abilities throughout their lives, mastering intricate techniques only by mid-adolescence.
- Importance of Lifelong Learning: The study highlights the evolutionary significance of prolonged learning periods in species that use tools, suggesting it is a trait shared with humans.
- Research Methodology: The findings are based on extensive video analysis of chimpanzees using tools in their natural habitat, providing a detailed look at the progression of their skills over many years.
Source: PLOS
Chimpanzees continue to learn and hone their skills well into adulthood, a capacity that might be essential for the evolution of complex and varied tool use, according to a study publishing May 7th in the open-access journal PLOS Biology by Mathieu Malherbe of the Institute of Cognitive Sciences, France and colleagues.
Humans have the capacity to continue learning throughout our entire lifespan. It has been hypothesized that this ability is responsible for the extraordinary flexibility with which humans use tools, a key factor in the evolution of human cognition and culture.
In this study, Malherbe and colleagues investigated whether chimpanzees share this feature by examining how chimps develop tool techniques as they age.
The authors observed 70 wild chimps of various ages using sticks to retrieve food via video recordings collected over several years at Taï National Park, Côte d’Ivoire. As they aged, the chimps became more skilled at employing suitable finger grips to handle the sticks.
These motor skills became fully functional by the age of six, but the chimps continued to hone their techniques well into adulthood. Certain advanced skills, such as using sticks to extract insects from hard-to-reach places or adjusting grip to suit different tasks, weren’t fully developed until age 15.
This suggests that these skills aren’t just a matter of physical development, but also of learning capacities for new technological skills continuing into adulthood.
Retention of learning capacity into adulthood thus seems to be a beneficial attribute for tool-using species, a key insight into the evolution of chimpanzees as well as humans. The authors note that further study will be needed to understand the details of the chimps’ learning process, such as the role of reasoning and memory or the relative importance of experience compared to instruction from peers.
The authors add, “In wild chimpanzees, the intricacies of tool use learning continue into adulthood. This pattern supports ideas that large brains across hominids allow continued learning through the first two decades of life.”
Funding: This study was funded by the Max Planck Society (M.IF.EVAN8103 – to CC and RMW through the Evolution of Brain Connectivity Project). LS was supported by the German Research Foundation (DFG, Emmy Noether Fellowship 513871869). The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.
About this evolution and neuroscience research news
Author: Claire Turner
Source: PLOS
Contact: Claire Turner – PLOS
Image: The image is credited to Neuroscience News
Original Research: Open access.
“Protracted development of stick tool use skills extends into adulthood in wild western chimpanzees” by Mathieu Malherbe et al. PLOS Biology
Abstract
Protracted development of stick tool use skills extends into adulthood in wild western chimpanzees
Tool use is considered a driving force behind the evolution of brain expansion and prolonged juvenile dependency in the hominin lineage.
However, it remains rare across animals, possibly due to inherent constraints related to manual dexterity and cognitive abilities.
In our study, we investigated the ontogeny of tool use in chimpanzees (Pan troglodytes), a species known for its extensive and flexible tool use behavior.
We observed 70 wild chimpanzees across all ages and analyzed 1,460 stick use events filmed in the Taï National Park, Côte d’Ivoire during the chimpanzee attempts to retrieve high-nutrient, but difficult-to-access, foods.
We found that chimpanzees increasingly utilized hand grips employing more than 1 independent digit as they matured. Such hand grips emerged at the age of 2, became predominant and fully functional at the age of 6, and ubiquitous at the age of 15, enhancing task accuracy.
Adults adjusted their hand grip based on the specific task at hand, favoring power grips for pounding actions and intermediate grips that combine power and precision, for others.
Highly protracted development of suitable actions to acquire hidden (i.e., larvae) compared to non-hidden (i.e., nut kernel) food was evident, with adult skill levels achieved only after 15 years, suggesting a pronounced cognitive learning component to task success.
The prolonged time required for cognitive assimilation compared to neuromotor control points to selection pressure favoring the retention of learning capacities into adulthood.
