Evaluate recent challenges to nativist theories of language development. Nativist’s beleive that language is acquired through the operation of innate factors and that biological maturation governs development (Mareschall et al. 2006). For the purpose of this paper the word “innate” will be used in the same context as Grayson et al. (2005) did. Nativists propose that children are born with a formal language system known as Universal Grammar (Chomsky, 1995). The environment, in their view, only plays a part in aiding infants decide which of the universal rules to apply (Mareschall et al. 2006).
To challenge the nativist view I will cover some aspects of language development where there is clear opposite views on how certain processes develop. The opposition is represented by empiricists, who believe that the environment is indispensable for development. The different approaches will be considered in light of their differences and ways in which they may contradict one another. Each theoretical point will be looked at alongside evidence from researches.
It is worth noting that whilst these theories seem to be total opposites they to not deny the existence of one another but differ in the importance they place on each element (Mareschall et al. 2006). Piaget believed that the quality of experiences from the physical and social world, together with the drive for equilibrium combines to produce developments. The interaction between genes and the environment is represented by epigenesis (Mareschall et al. 2006).
Theories that acknowledge that one another exist is well represented by the debate of modularity vs. modularisation, this debate was notably pursued by Fodor and Karmiloff. Both theories stand equal on their view of the brain working in a modular fashion and consisting of modular units (Mareschall et al. 2006). Modules refer to functional units that specialise in processing certain types of information (Mareschall et al. 2006).
The divide lies in how these modules develop. Fodor (1983) represents the nativist side for modularity, a view that humans are born with the “innate capability to develop information processing systems that allow them to make sense of the world in which they have evolved” (Mareschall et al. 2006 p.127). The environment is represented in a phylogenetic sense and not as a crucial part in understanding an individual’s development, known as an ontogenetic sense (Mareschall et al. 2006).
Karmiloff-Smith (1992) takes a more epigenetic viewpoint. In her view “if the mind ends up with any modular structure, then, even in the case of language, the mind becomes modularised as development proceeds” (Karmiloff-Smith 1992, p.158). Karmiloff suggests a developing process of modularisation that “occurs repeatedly as the product of development” (Karmiloff-Smith 1992, p.158). Karmiloff does not reject the view of domain specific knowledge but rather that it occurs with time as a result of an interaction between the genes and the environment.
Whilst behaviourists such as Skinner (1953) suggested that infants are tabula rasa or blank slates ready to take on domain-general learning processes Piagetians believe infants to be active agents in learning (Karmiloff-Smith 1992, p.159). Through studying disorders such as autism and Williams Syndrome, findings seem to point towards domain-specificity as whilst higher cognitive functions become impaired other areas seem moderately unharmed thus supporting nativism (Karmiloff-Smith, 1992). However this does not consider the flexibility of the brain known as plasticity (Karmiloff-Smith, 1992).
Self organisation “occurs when a structure emerges in response to a system’s dynamic interaction with an environment” (Mareschall et al. 2006 p. 192). Karmiloff suggests that the brain is a self organisation system. Donald Hebb’s (1949) influential work in neuropsychology supports this view. The Hebb rule implies that the more the neurones are activated the easier they then activate one another thus strengthening the neural pathways. This learning model can be applied to language; it strengthens through repeated usage (Mareschall et al. 2006). To strengthen this theory it is worth noting that in a system as complex as the brain the infinite possibilities of outcome that may be produced is an indication of the impossibility of it being pre-specified (Elman et al. 1996). It is important when debating nature vs. nurture to incorporate neuroscientific evidence.
Nativists argue that there is “an identifiable seat (for language) in the brain” (Pinker, 1994, p.45). Indeed the left temporal lobe has been unmistakably associated with language in adults however researchers such as Neville et al. (1998) have studied the concept of equipotentiality. This concept proposes that at birth each side of the brain has equal potential for developing language. The question for neuroscience lies in whether the left temporal lobe is critical for language development or if there are other cortical regions that can perform the task (Mareschall et al. 2006). The studies in this field draw conclusion that other cortical regions are able to support language however a full equipotential view is dismissed.
Neville et al. (1992) used ERPs (brain imaging technique) to suggest that grammatical and semantic information were responded to differently by the brain (Mareschall et al. 2006). He concluded with an epigenetic view stating that “there are constraints on the organisation of the neural systems that mediate formal language … however, it is clear that the nature and timings of sensory and language experience significantly affect the development of the language system in the brain” (Neville and Bavelier, 2001, p.283).
One aspect that nativists do not give much credit to is the plasticity of the brain. Cases of feral children such as Genie who were unable to learn language after having being isolated for many years support the nativits. However studies on localised brain damage that has occurred before or during birth have raised more challenges for language being innate. The continuous functional recovery that is displayed after focal lesions and the brain’s ability to recuperate functional damage by other part of the cortex gives an outstanding example of how adaptive the brain is and a strong case against the brain being genetically pre-wired (Reilly et al. 1998).