Arbib 1 Tool Use and Constructions Commentary on Krist Vaesen (2012) The cognitive bases of human tool use. Behavioral and Brain Sciences. Michael A. Arbib Computer Science, Neuroscience and USC Brain Project University of Southern California, Los Angeles, CA 90089-2520, USA 1-213-740-9220 arbib@usc.edu Arbib, M. A. (2012). Tool use and constructions. Behavioral and Brain Sciences, 35, 218-219. Abstract We examine tool use in relation to the capacity of animals for construction, contrasting tools and nests; place human tool use in a more general problem-solving context, revisiting the body schema in the process; and relate the evolution of language and of tool use. Main text Tools versus Nests: Many creatures can use tools of a specific kind and in come cases even make them, as do New Caledonian crows (Hunt, 1996; Weir, Chappell, & Kacelnik, 2002). Lefebvre et al. (2002) conclude that the complex cognitive processes involved in tool use may have independently co-evolved with large brains in several orders of corvine and passerine birds. Nonetheless, it seems to me that nest building by birds is even more impressive than their tool making and, indeed, Hansell & Ruxton (2008) urge that we view tool behaviors as a limited subclass of construction behavior. Nest building in birds has been a key driver of habitat diversification and speciation in these groups (Collias, 1997; Hansell, 2000). It is thus intriguing that Stewart, Piel, and McGrew (2011) show that re-use of specific nest sites by savanna chimpanzees may be a result of “niche construction” (Iriki & Taoka, 2011; Laland, Odling-Smee, & Feldman, 2000) through formation of good building sites within trees. They speculate that environmental modification through construction behavior may have influenced both chimpanzee and early hominin ranging by leaving behind recognizable patterns of artifact deposition across the landscape. Human Tool Use in Construction: Let’s shift attention from “using a tool” to the ability to deploy multiple tools to solve a problem. To join a piece of wood to the wall, I may employ a screw of sufficient length plus a screwdriver; or a nail and hammer. I may also employ a stud finder, but if I need to affix an object where there is no stud, I deploy a rawlplug, a drill and a hammer to prepare for the screw. For household repair, I may deploy these tools and more to solve a truly novel problem by breaking it down into subproblems for which I have routine solutions. Or I may call in a handy-man, thanks to the great specialization within human society, and the social construction of monetary incentives. An etymological detour, based on the Oxford English Dictionary: Handiwork, “a thing made by the hands,” comes from Old English hand + geweorc. As geweorc ≈ iwork did not survive in Middle English, hand-iwerc was reanalyzed as a compound of werc with handi. This was eventually treated as an adjective, handy, meaning “of, or done by, the