* Lack of Semantic Content: Interjections primarily convey emotion or reaction rather than carrying specific meaning. They don't refer to objects, actions, or concepts. This contrasts with the fundamental purpose of language: to communicate information and ideas.
* Limited Linguistic Structure: Interjections rarely integrate into grammatical structures. They're often uttered alone, lacking the complexities of verbs, nouns, and adjectives.
* Cross-Cultural Variation: Interjections tend to be highly variable across languages and cultures. While some interjections might be similar, their exact sounds and meanings can differ significantly, suggesting they didn't arise from a common source.
* Emotive Origin: Interjections are thought to have evolved from instinctive vocalizations like cries, groans, or sighs. This contrasts with the gradual development of language through more complex processes of sound manipulation and symbolic association.
* Developmental Trajectory: Children typically learn to use interjections earlier than other parts of language, suggesting they're more instinctive and less dependent on complex cognitive development.
Therefore, interjections are considered less likely to be the building blocks of human speech sounds because:
1. They lack semantic content and linguistic structure.
2. They exhibit significant cross-cultural variation.
3. They are rooted in instinctive vocalizations rather than deliberate sound manipulation.
4. Their early emergence in children suggests they are more innate and less culturally influenced.
While interjections don't necessarily contribute to the evolution of language as we know it, they play a vital role in human communication by expressing emotions and reactions, making them an essential part of our expressive repertoire.