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The Tool With a Capital T

Scientists in the field have an unparalleled fascination with tools1, you know, those objects that we most often manipulate with our hands. It can be a hammer, screwdriver, fork or branch, as long as it is used to interact with the environment. It is true that tools reflect an important part of our materiality. However, should we consider that such a fascination is justified? I think you anticipate my answer to that question: no. No, the tools are not the only reflection of our materiality, far from it. Worse, being so fascinated by these tools that we consider them as the only subject of study of human materiality can lead to a lack of understanding of the underlying cognitive mechanisms.

Let us do a fairly simple exercise. Take a quick look around you. What do you see? Certainly a pen, a computer, books, furniture, a desk, walls, maybe even a road, if you are near a window, with cars and trucks driving on it. Leave your house or apartment, and imagine yourself now on a plane, near a window, looking at the ground - if you are not already there after all. What do you see? Again, roads, buildings, bridges, even cities. Let us now travel back in time. Think of the Middle Ages, Antiquity, or Ancient Egypt. What are you thinking about? Castles, carriages, arenas, pyramids, wooden boats, etc. This is a trivial exercise, I admit. However, the answers provided are irrevocable. We are not only tool users, we are also builders, and we excel so much in this field that it is even possible to see some of our constructions from space (the Great Wall of China for example). How can scientists then justify the need to focus so much on tools while neglecting the most important traces of our materiality? We are constantly changing our physical environment. We are building, constructing, demolishing, only to rebuild again. The result of this appetence is staggering. However, scientists are not interested in this. They are interested in understanding how we manipulate tools - usually with our hands - and rarely focus on our ability to make them. For me, this excessive fascination is detrimental to understanding what characterizes us as humans, precipitating generations of researchers toward the quest for the famous motor programs useful for manipulating tools, as if a human were only a tool manipulator, and not a maker or a builder.

My positioning will be different, and you will have understood that. In this book, I defend the idea that tool use, tool making and construction behavior are the three sides of the same piece that I call the Tool with a capital T. And it is only by understanding the cognitive bases of the origin of these three behaviors that it is possible to develop a new field of research on the Tool, thus escaping from this fascination for use or, rather, for manipulation - or even for the hand. This first chapter is intended to expand on this point. I will begin by defining the three behaviors mentioned above, characteristics of our materiality. I will then discuss the epistemological reasons behind scientists' fascination with tools. I will continue by discussing the implications of this fascination for the choice of useful animal models, and for the idea that specific cognitive abilities could be associated with each of these three behaviors.

1.1. Defining the Tool: the behavioral reality

Traditionally, the notion of tool refers to any manipulable physical object that is used to cause changes in other objects in the environment. A nail is not a tool, unlike the hammer used to drive it in. Similarly, a house is not a tool, unlike the trowel used to build it. Table 1.1 summarizes the definitions proposed by major authors in disciplines around anthropology, psychology and neuroscience. As can be seen, all these definitions agree on a major criterion, namely that the tool is what is manipulated during use. I will refer to this criterion as the criterion of manipulation.

Field Author(s) Definition Primatology (van Lawick-Goodall 1970, p. 195) [Tool use is] the use of an external object as a functional extension of mouth or beak, hand or claw, in the attainment of an immediate goal. Psychology (Gibson 1979, p. 41) When in use, a tool is a sort of extension of the hand, almost an attachment to it or a part of the user's own body, and thus is no longer a part of the environment of the user. But when not in use, the tool is simply a detached object of the environment, graspable and portable, to be sure, but nevertheless external to the observer. Ethology (Beck 1980, p. 10) Tool use is the external employment of an unattached environmental object to alter more efficiently the form, position, or condition of another object, another organism, or the user itself when the user holds or carries the tool during or just prior to use and is responsible for the proper and effective orientation of the tool. Neuropsychology (Ochipa et al. 1992, p. 1063) A tool was defined as an implement for performing or facilitating mechanical operations, such as a screwdriver. An object was defined as a thing to which mechanical action is directed, such as a screw. Ergonomics (Baber 2003, p. 8) A tool is a physical object that is manipulated by users in such a manner as to both affect change in some aspect of the environment and also to represent an extension of the users themselves. The manipulation is directed toward a specific goal or purpose, and the associated activity requires a degree of control and coordination. Cognitive neuroscience (Frey 2007, p. 368) Tools [are] manipulable objects that are used to transform an actor's motor output into predictable mechanical actions for purposes of attaining specific goals (i.e., motor-to-mechanical transformations). Computer science (St Amant and Horton 2008, p. 1203) Tool use is the exertion of control over a freely manipulable external object (the tool) with the goal of (1) altering the physical properties of another object, substance, surface or medium (the target, which may be the tool user or another organism) via a dynamic mechanical interaction, or (2) mediating the flow of information between the tool user and the environment or other organisms in the environment.

Table 1.1. Major definitions of tool use

If we follow this behavioral definition of the phenomenon, a number of observations of animal behavior can be categorized as tool use (see Table 1.2), whether in non-human primates, non-primate mammals, or birds, and even, more unexpectedly, in fish or insects. In some cases, the repertoire may be relatively varied, such as in chimpanzees, in which nearly 40 behaviors may have been listed throughout the species (Whiten et al. 1999). In other species, this may characterize a single behavior, sometimes observed in an isolated individual, such as the observation of a gorilla using a branch to probe a pond before entering it (Breuer et al. 2005).

Species Tool Function Activity Insect, fish Ant Sand To throw Projected with the head Archerfish Water To throw Water sprayed on prey Bird Egyptian vulture Stone To pound Held in the beak Galápagos finches Twig To probe Held in the beak Seagull Rock To throw Released in flight Non-primate mammal Elephant Branch To whip Held by the trunk Polar bear Rock To throw Held between the claws Primate Chimpanzee Twig To probe Held between the legs Chimpanzee Branch To pound Held between the legs Chimpanzee Branch To split Held between the legs

Table 1.2. Animal tool use

Tool use is to be differentiated at the behavioral level of tool making and construction behavior. The definitions associated with each of these behaviors are provided in Table 1.3 based on the categorization provided by Shumaker et al. (2011), which lists all of these behaviors in the animal kingdom. In short, construction consists of assembling objects in order to build a semipermanent entity, without this entity being manipulated during its use. Nest building is a prime example of this behavior and is frequently observed in the wild. Tool making shares with construction the criterion of assembling objects, although making may also refer to other modes (see...