Online research in philosophy

The structuring of our environment to provide cues and reminders for ourselves is common: We leave notes on the fridge, we have a particular place for our keys where we deposit them, making them easy to find. We alter our world to streamline our cognitive tasks. But how did hominins gain this capacity? What pushed our ancestors to structure their physical environment in ways that buffered thinking and began the process of using the world cognitively? I argue that the capacity to engage in these behaviours is a by-product of increased tool investment and tool curation, which in turn was necessary because of increasingly heterogeneous environments. The minute tools are carried and cared for, they begin to undergo selection for added functions, becoming available as cognitive primers and as signals. I explore the trajectory of this co-evolutionary feedback loop of hominins and their tools, and demonstrate the role tools have in shaping our thinking.

In this commentary, we propose that the shifts in symmetry Wynn documents may be explained in terms of simpler mechanisms than he suggests. Furthermore, we argue that it is dangerous to draw definitive conclusions about the cognitive abilities of a species from the level of symmetry observed in the artefacts produced by that species.

Wynn suggests that the imposition of symmetry on stone tools is indicative of the evolutionary development of cognitive abilities of the tool makers, particularly that of creating mental images. I suggest that it is more likely indicative of the evolutionary development of the perceptual ability to detect resources for behavior of hand-held objects.

Long before signs of staged toolmaking appeared, Homo erectus made symmetrical tools. The handaxe is a flattened tear-drop shape, but often with edges sharpened all around. Before we assign their obsession with symmetry to an aesthetic judgment, we must consider whether it is possible that the symmetry is simply very pragmatic for one particular use in the many suggested.

This article questions traditional experimental approaches to the study of primate cognition. Beecuse of a widespread assumption that cognition in non-human primates is genetically encoded and “natural,” these approaches neglect how profoundly apes’ cultural rearing experiences affect test results. We deseribe how three advanced cognitive abilities - imitation, theory of mind and language - emerged in bonobos maturing in a bi-species Pan/Homo culture, and how individual rearing differences led to individual forms of these abilities. These descriptions are taken from a rich ethnographic material, and we argue for the scientific superiority of participant-based ethnographic studies of primate cognition in shared Pan/Homo cultures.

Dubreuil (Biol Phil 25:53–73, 2010b , this journal) argues that modern-like cognitive abilities for inhibitory control and goal maintenance most likely evolved in Homo heidelbergensis , much before the evolution of oft-cited modern traits, such as symbolism and art. Dubreuil’s argument proceeds in two steps. First, he identifies two behavioral traits that are supposed to be indicative of the presence of a capacity for inhibition and goal maintenance: cooperative feeding and cooperative breeding. Next, he tries to show that these behavioral traits most likely emerged in Homo heidelbergensis . In this paper, I show that neither of these steps are warranted in light of current scientific evidence, and thus, that the evolutionary background of human executive functions, such as inhibition and goal maintenance, remains obscure. Nonetheless, I suggest that cooperative breeding might mark a crucial step in the evolution of our species: its early emergence in Homo erectus might have favored a social intelligence that was required to get modernity really off the ground in Homo sapiens.

Using neoPiagetian theory of mental attention (or working memory), I task-analyze two complex performances of great apes and one symbolic performance (funeral burials) of early Homo sapiens. Relating results to brain size growth data, I derive estimates of mental attention for great apes, Homo erectus, Neanderthals, and modern Homo sapiens, and use children's cognitive development as reference. This heuristic model seems consistent with research.

Evolutionary theories of human cognition should refer to specific times in the primate or hominid past. Though alternative accounts of tool manufacture from Wynn's are possible (e.g., frontal lobe function), Wynn demonstrates the power of archaeology to guide cognitive theories. Many cognitive abilities evolved not in the “Pleistocene hunter-gatherer” context, but earlier, in the context of other patterns of social organization and foraging.

Despite challenges on minimum necessary competence, intentionality, reliability, and context, the example of cognitive archaeology presented in the target article holds up well. The commentaries also present perspectives on cognition and symmetry that suggest an alternative to the target article's characterization of the cognitive abilities of early Homo erectus. However, the major conclusion of the initial argument – that the human ability to coordinate shape recognition and spatial cognition evolved hundreds of thousands of year ago in conditions unlike those of the modern world – remains intact.

Archaeology can provide two bodies of information relevant to the understanding of the evolution of human cognition – the timing of developments, and the evolutionary context of these developments. The challenge is methodological. Archaeology must document attributes that have direct implications for underlying cognitive mechanisms. One example of such a cognitive archaeology is found in spatial cognition. The archaeological record documents an evolutionary sequence that begins with ape-equivalent spatial abilities 2.5 million years ago and ends with the appearance of modern abilities in the still remote past of 400,000 years ago. The timing of these developments reveals two major episodes in the evolution in spatial ability, one, 1.5 million years ago and the other, one million years later. The two episodes of development in spatial cognition had very different evolutionary contexts. The first was associated with the shift to an open country adaptive niche that occurred early in the time range of Homo erectus. The second was associated with no clear adaptive shift, though it does appear to have coincided with the invasion of more hostile environments and the appearance of systematic hunting of large mammals. Neither, however, occurred in a context of modern hunting and gathering. Key Words: Archaeology; evolution; Homo erectus; spatial cognition; symmetry.