1. Do Nature and Nurture Play Similar Roles in Speech Development?
Several schools of thought exist regarding the nature v. nurture debate regarding language development. Language is a representation of inner speech and inner speech is a function of thought processing (Lollar, Monsour, & Barwind, 2012, pp. 62). We are hard-wired to acquire speech within a window of time; failure to acquire speech within that window can result in ever fully mastering a speaking skill (Feldman, 2010). It is impossible to disentangle nature from nurture in the acquisition of speech; both are important (Lollar, Monsour & Barwind, pp. 62). By the nature of our brain development, we are capable of developing speech capacity, but this is time limited. Our environment dictates the type of speech we develop: language and dialect, how and what is appropriate to express, and the language used to express it including non-verbal communication (Feldman). Nurture plays a critical role in speech development, probably more than nature, because we are all genetically capable of speech communication, but it is our environment that determines if we reach the level of our capacity and in what way we do it.
2. Linguistic Views
There are three primary linguistic view, the first of which is the nominalist view which suggests that we all perceive things the same way regardless of the language we use to express it, therefore perception does not shape language (Teacher Last Name, 2016), an idea developed by Chomsky and referred to as nativist (Braine, 2008; Feldman, 2010). I do not agree with this for the simple reason that if you have never seen snow you have no language to describe it. The relativist view states that the language we speak dictates the way we perceive our world (Teacher Last Name) similar to the interactionist approach Feldman describes. The example given was the Navajo language having no possessives. The problem with this theory is that if there is never a need to think an idea, there is no need to develop the expression of the idea into language. The Qualified Relativist view says that language and perception both influence each other (Teacher Last Name): if you perceive it, a language (or words) are developed that will allow you to express your perception.
References
Braine, M. D. S. (1994). Is nativism sufficient? Journal of Child Language, 21,pp 9-31 [abstract].
Feldman, R. (2010). Psychology and your life. Boston: McGraw-Hill.
Lollar, K., Monsour, M., & Barwind, J., Editors. (2012). The Talk Within: Its Central Role in Communication. Dubuque, Iowa: Kendall Hunt.