Language and Thought
How Are Language and Thought Connected?
Psychologists disagree about which comes first: the ability to think, or the language we use to express our thoughts. Two theorists give very different answers — Jean Piaget and Lev Vygotsky — and a separate debate asks whether the specific language you speak shapes what you are able to think at all.
Piaget: Thought Comes Before Language
Piaget argued that representational thought develops before language. A child must first build a mental concept — such as understanding that objects continue to exist when they are out of sight — before they can attach words to that idea.
For Piaget, language is a label placed on top of thinking that has already happened. A toddler who reaches behind a cushion for a hidden toy has already grasped the concept of object permanence; the words “it’s there” come afterwards. Cognitive development drives language development, not the other way round.
Piaget argued that thought comes before language: children build a mental concept first, then attach words to it once the concept already exists.
Vygotsky: Two Separate Systems That Merge
Vygotsky took a different view. He argued that language and thinking start out as two separate systems in the young child. Pre-linguistic thought is thinking that has not yet been connected to words at all. At the same time, pre-intellectual language — crying, babbling, early social sounds — carries no real thinking behind it; it is simply communication.
Vygotsky proposed that at around age two, these two separate lines join together. Once this happens, speech becomes a tool for thinking — what Vygotsky called inner speech. From this point on, language does not just express thought; it actively shapes and advances it, because words let a child hold onto and manipulate ideas that would otherwise be too complex to keep in mind.
Vygotsky argued that language and thought begin as separate systems — pre-linguistic thought and pre-intellectual language — that merge at around age two, after which speech becomes a tool for thinking.
Comparing Piaget and Vygotsky
Both theorists agree that thought does not begin purely as a product of words — some thinking exists before or separately from language. But they disagree about what happens next. Piaget saw language as permanently dependent on thought throughout development: thought always leads, language always follows. Vygotsky saw the two as independent systems early on that then fuse, after which language becomes an active, shaping force on thought rather than a passive label.
A strength of Piaget’s view is that it is supported by evidence that young children grasp concepts, such as object permanence, before they have the words to describe them — suggesting thought really can exist without language. A weakness is that it does not explain why learning a new word can sometimes introduce a genuinely new way of thinking, which Vygotsky’s account handles more easily.
A strength of Vygotsky’s view is that it explains both the early independence of thought and language and the later, more complex relationship between them once inner speech develops. A weakness is that the exact age and process of merging is difficult to test directly, since very young children cannot easily report their own thinking.
Linguistic Relativism and Linguistic Determinism
A separate debate asks whether the specific language a person speaks affects what they are able to think, not just when thinking develops. Linguistic determinism is the strong version of this idea: it claims that language completely controls thought, so a person can only think thoughts for which their language has words.
Linguistic relativism is the weaker, more widely accepted version. It claims that language influences thought — making certain ideas easier or harder to hold in mind — without making it impossible to think beyond your own language’s categories.
Aim: Boroditsky (2001) tested whether the spatial metaphors built into a language affect how its speakers think about time. Mandarin commonly uses vertical metaphors for time (earlier events are described as ‘up’, later events as ‘down’), while English mainly uses horizontal, front-to-back metaphors (looking ‘forward’ to the future).
Procedure: Mandarin and English speakers were shown vertical or horizontal spatial arrangements and then asked to judge temporal statements. English speakers were also trained to describe time using vertical spatial language.
Results: Mandarin speakers judged temporal statements faster after seeing vertical spatial arrangements, while English speakers judged them faster after horizontal arrangements. English speakers who were trained to use vertical time metaphors began to think about time more like Mandarin speakers did.
Conclusion: The habitual metaphors built into a language shape how its speakers think about abstract concepts like time. Because English speakers’ thinking could be changed through training, the findings support linguistic relativism rather than strict linguistic determinism.
Boroditsky (2001) found that Mandarin speakers think about time using vertical spatial metaphors and English speakers use horizontal ones — and that English speakers’ thinking could be shifted through training, supporting linguistic relativism over strict determinism.
Evaluating the Language and Thought Debate
Linguistic determinism in its strong form is generally rejected: people regularly think thoughts for which they have no existing word, and then coin a new word to describe them, which would be impossible if language fully controlled thought. Linguistic relativism has more support, particularly from studies like Boroditsky’s, but the size of the effect is debated and it is hard to separate the influence of language from the influence of culture more broadly.
Most modern psychologists take an interactionist position: language and thought shape each other, rather than one simply causing or following the other.