The Swiss Army Knife vs the hand

Another set of contrasting views has to do with whether the human mind has evolved with a set of specialist cognitive capacities, or is more generalist. An analogy that has been used is the Swiss Army Knife which has a set of different tools to perform different functions. This Evolutionary Psychology (EP) view has been promulgated mainly by Cosmides and Tooby (1992, 2011). The term is capitalized to distinguish it from the general topic of evolutionary psychology as it takes a particular view of how human behaviour and thinking have evolved. The human mind, they argue, has evolved a range of specific adaptations to the physical and social environment in which hominids found themselves during the Pleistocene. According to this view, the mind is composed of a large number of domain specific modules. As well as modules that deal with language, aspects of vision, social interaction and so forth, there are also modules responsible for human thinking and reasoning. Cosmides and Tooby (2011) assert that: ‘all normal human minds reliably develop a standard collection of reasoning and regulatory circuits that are functionally specialized and, frequently, domain-specific' (p. 3). According to their Principle 4, there are different, specialized ‘universal reasoning circuits’ to solve different adaptive problems. They take issue with the idea that there is a general purpose, context-free intelligence and regard computational systems underpinning reasoning and learning circuits as essentially instincts.

In contrast to EP, the new thinking (NT) view regards the hand as the appropriate metaphor for recently evolved human cognition (Jablonka, 2011). The hand is a general-purpose tool that can be used for a variety of tasks. Our ability to adapt to a very wide range of environments and to engage in scientific, literary, and artistic creation suggests a domain general cognitive system. NT, therefore, rejects the idea of massive modularity and takes a longer view of human evolution since humans had inherited mental and physical structures from before the Pleistocene. Heyes (2003, 2012) discusses the importance of incremental co-evolution, particularly social and technical evolution developing together. For example, selection pressures favouring technical skills support the evolution of social skills, in turn, creating a positive feedback loop. She argues that a different type of co-evolution involving both genetics, epigenetics (how gene expression is modified through experience during development) and cultural learning, creates the kinds of domain specific circuits we can observe in the brain. Furthermore, the cultural environment can itself create an evolutionary pressure. A typical example is lactose tolerance which evolved in cultures that domesticated livestock.

Another example is that of reading which is not an ability that we have evolved since near universal literacy is very recent. Reading, therefore, must have co-opted circuits that had evolved for different reasons. An area in the left midfusiform gyrus at the junction of the left occipital and temporal lobes in the brain is activated only in the presence of written letters (Dehaene et al., 2010) so it looks like one of EP's specific evolved brain circuits. The debate between the hand and the Swiss army knife has still some way to run.

Although we have been discussing the evolutionary underpinnings of human thinking, our behaviour is not entirely governed by them. Culture, upbringing, and the ability to reason can mitigate and control our natural impulses. Our future is not determined by our genetic inheritance: ‘We are not restricted to the modes of thought that come with our evolutionary and social inheritance, but - by thinking about thought - we have the ability to develop new and better ways of thinking’ (Bayne, 2013).