1. This theory is broader than the prior theory, which held that thought was derived from speech production, since it encompasses all of language, both speech production and speech understanding.
2. The relationship of language, thought, and culture is a topic that is central to psycholinguistics.
3. Can we distinguish a 'safe' from a 'harmful' second language?
3.1. If teaching a second language to children is antithetical to the morals and values of the society in which they live, then clearly children should not be taught a second language.
4. Four theories regarding the dependence of thought and culture on language
4.1. Theory 1:
4.1.1. Speech is essential for thought. We must learn how to speak aloud, otherwise we cannot develop thinking.
4.2. Theory 2:
4.2.1. Language is essential for thought. We must learn language, how to produce or understand speech, otherwise we cannot develop thinking.
4.3. Theory 3:
4.3.1. Language determines or shapes our perception of nature. The learning of language will determine or influence the way we perceive the physical world, visually, auditorily, etc.
4.4. Theory 4:
4.4.1. Language determines or shapes our world view. The learning of language will determine or influence the way we understand our culture and the world.
5. Speech is essential for thought
5.1. The comprehension and production processes develop in a parallel mode with production always trying to keep up with comprehension.
5.2. The child attempts to coordinate production with respect to the system that has been developed for understanding
6. Behaviourists
6.1. Behaviour of the body is essential for thought
6.2. Skinner suggested that behavioural responses could be the basis of thought in addition to speech utterances.
7. Language is essential for thought
7.1. Proponents of the theory
7.1.1. Sapir, Whorf, and Vygotsky.
7.2. Thought is not merely expressed in words; it comes into existence through them.
8. Language determines or shapes our perception of nature
8.1. Proponents of the theory
8.1.1. Whorf, Sapir, Korzybski, and others.
8.2. Psychologists have tried experimentally to determine what effects, if any, knowledge of the vocabulary of language has on perception or behaviour.
9. There is no foundation to the claim that vocabulary affects our view of nature.
9.1. In fact, the evidence shows the reverse to be true. One would think that on such an important issue, the proponents of the theory would offer sound evidence in support of their view.
10. Language determines or shapes our cultural world view
10.1. Proponents of the theory
10.1.1. Some theorists believe that even if language is somewhat distinct from thought, nevertheless, knowing a language will itself condition and influence one's cultural, social beliefs or views of the world.