This book features a chapter by Andy Clark entitled: How to Qualify for a Cognitive Upgrade: Executive Control, Glass Ceilings, and the Limits of Simian Success. Here is the intro to the chapter:

10.1 Introduction

It is sometimes suggested that words and language form a kind of ‘cognitive niche’ (Clark, 1998, 2005, 2006, 2008; Chapter 4): an animal-built structure that productively transforms our cognitive capacities. But even if language cognitively empowers us in many deep and unobvious ways, it would be quite wrong to assume that such empowerment occurs in either a neural or an evolutionary vacuum. In evolutionary terms, we need to recognise the various precursors of our own prodigious skills at species-level selfscaffolding. In neural terms, we need to uncover the specific innovations that allow certain kinds of agents to benefit (humans massively, simians somewhat, hamsters not at all) from the empowering effects of exposure to a public linguistic edifice. What we need to understand is thus a delicate balancing act between extra-neural and neural innovation, such that the public material structures of language are enabled (in some beings and not in others) to play significant cognitive roles. In the present chapter, I first lay out a few of the ways in which language may indeed act as a potent form of cognitive scaffolding. I then briefly rehearse the results of a series of elegant comparative and developmental studies (summarised in McGonigle and Chalmers [2006]) that suggest a surprising amount of evolutionary continuity between human and simian (squirrel monkey) subjects in respect of some of the key ‘building block’ skills that enable this potent ‘mind-tool’ (Dennett, 2000) to emerge. I end by asking, ‘What then limits simian success?’