A new paper published in Current Biology shows the similarities in adopting the same tactics for remembering where things are between human infants and apes. Differences arise as human children begin to develop their strategies.

There are two basic strategies animals use to remember spatial information; either the the individual remember a thing’s features, such as whether it was a banana, or they remember its place in space, such as left of this object.

Testing conducted on other species of animals show that animals such as chickens and toads, prefer a feature-based strategy. Others, such as fish and dogs, favor a place-based strategy. Daniel Haun, of the Max Planck Institute for Evolutionary Anthropology, and his colleagues extended their tests orangutans, gorillas, bonobos, chimpanzees and humans. They wanted to see whether humanity and its closest relatives all adopted the same strategies for remembering where things are. Any changes in strategy between species or within species would indicate on how they all evolved such behaviors like foraging patterns.

The paper, “Evolutionary Psychology of Spatial Representations in the Hominidae” documents the methodology Haun and his team operated on. They initially hid rewards such as grapes, banana slices or toy animals under either a hollow piece of wood, an imitation bird’s nest or an artificial hollow rock. At times, the rewards were concealed under the same object they were hidden beneath previously, whose place had changed. A feature-based strategy would best find these coveted items. And at other times, the rewards were hidden at the same place they were concealed before, but under a different object. A place-based strategy would best discover these items.

The abstract writes about the continuity between our species and the other great apes is masked early in human ontogeny,

“Comparatively little is known about the inherited primate background underlying human cognition, the human cognitive “wild-type.” Yet it is possible to trace the evolution of human cognitive abilities and tendencies by contrasting the skills of our nearest cousins, not just chimpanzees, but all the extant great apes, thus showing what we are likely to have inherited from the common ancestor [1]. By looking at human infants early in cognitive development, we can also obtain insights into native cognitive biases in our species [2]. Here, we focus on spatial memory, a central cognitive domain. We show, first, that all nonhuman great apes and 1-year-old human infants exhibit a preference for place over feature strategies for spatial memory. This suggests the common ancestor of all great apes had the same preference. We then examine 3-year-old human children and find that this preference reverses. Thus, the continuity between our species and the other great apes is masked early in human ontogeny. These findings, based on both phylogenetic and ontogenetic contrasts, open up the prospect of a systematic evolutionary psychology resting upon the cladistics of cognitive preferences.”

When human infants are a year old, they favor place-based strategies like all the other great ape species do. This suggests human and ape brains start out the same, at least when it comes to remembering where things are. The most recent common ancestors between humans and all the other great apes date back to about 15 million years ago, suggesting this common preference has been part of our brain structures since at least then. However, three-year-old children preferred a feature-based strategy. The researchers noted this shift in strategy coincided with a period when humans are first drawn into social life and acquire skills such as spoken language.

Cross posted on Anthropology.net, “Human Infants and Non-Human Great Apes remember spatial objects similarly.”

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