Chimpanzees are constantly surprising us by demonstrating advanced conceptual thinking, like understanding that other people can have false beliefs. Now researchers at the University of Washington in St Louis have recorded videos of chimp parents actively teaching their young how to use tools, as opposed to the skills being passed down through observation alone. The mothers not only understand the child's needs, but they find ways to offset the negative impact sharing tools has on their own ability to gather food.
The videos were shot in the Goualougo Triangle in the Republic of Congo by remote cameras set up to monitor termite mounds that are a favorite feeding ground of the local chimpanzee population. Here, the apes poke "fishing probes" crafted from particular plants into the mounds to pull out tasty termites – a behavior first noted by Jane Goodall in the 1960s.
"Wild chimpanzees are exceptional tool users, but in contrast to humans, there has been little evidence to date that adult chimpanzees teach youngsters tool skills," says Stephanie Musgrave, first author of the study.
Chimps have long been thought to learn tool use techniques by observing others, but according to the researchers, this is the first documented evidence of the animals actively teaching their young in a manner that satisfies the scientific criteria for teaching. The mothers were seen transferring their own tools to the kids, as well as coming up with ways to do so that let them continue gathering food themselves.
Identifying teaching among wild animals is difficult because one has to quantify the impact of possible teaching behaviors on both the teacher and the learner," says Musgrave. "Using video footage from remote camera traps placed at termite nests in the chimpanzees' home range, we were able to observe and quantify how sharing tools affected those who relinquished their tools as well as those who received them."
In the team's videos, the chimps are seen handing tools to the youngsters and going to find a new one for themselves, swapping and fixing probes, or even breaking them in half so mother and child can both fish.
"It is easy for us to take for granted the importance of sharing information to learn complex skills, as it is ubiquitous in humans," says Crickette Sanz, co-author of the study. "Our research shows that the evolutionary origins of this behavior are likely rooted in contexts where particular skills are too challenging for an individual to invent on their own."
The researchers believe that their findings will help build a better understanding of how humans developed culture and technology, how chimpanzees may do the same over time, and just what cognitive processes are involved in teaching.