Why are humans the only species that can talk? - BBC World Service

Key Concepts

Hyoid bone: A unique bone supporting the tongue and larynx, crucial for complex human speech.
FOXP2 gene: A gene linked to language evolution, with a specific human mutation controlling communication centers in the brain.
Linguistic capacity: The ability to use and understand language.
Gestural theory: The hypothesis that language originated from gestures.
Tool-making theory: The idea that cognitive skills for tool creation also facilitated language development.
Social bonding/gossiping theory: The theory that speech evolved to maintain social cohesion in large groups.
Innate capacity for language (Chomsky): The concept that humans are born with a hardwired ability for language.
Ancient DNA: Genetic material from past organisms used to study evolutionary history.
Artifacts: Objects made by humans, providing clues about past cultures and behaviors.
Clicks (linguistics): A type of consonant sound found in some African languages, hypothesized to be present in early human languages.

Anatomical and Genetic Foundations of Speech

The ability for complex human speech is deeply rooted in specific anatomical and genetic features. The hyoid bone, a tiny bone located at the top of the neck, is critical as it supports the tongue and larynx. While this bone is present across the animal kingdom, allowing species like howler monkeys to make sounds, its unique shape in humans enables the formation of more complex speech.

Analysis of fossils indicates that linguistic capacity was present in humans at least 135,000 years ago. Further insights come from studying ancient DNA, particularly the FOXP2 gene. This gene is strongly linked to the evolution of language and is found in early modern humans and their predecessors, the Neanderthals. Although the FOXP2 gene is present in a wide range of vertebrates (including primates, birds, and fish), humans possess a specific mutation of this gene, which plays a crucial role in controlling communication centers in the brain. This unique combination of anatomy and cognition is not observed elsewhere in the animal kingdom and is considered the reason for the sophistication of human language.

Theories of Language Origin

The exact origins of human language remain a subject of ongoing debate, as direct evidence from the past is unattainable. However, linguistic experts have developed several "educated guesses":

Gestural Theory: One perspective suggests that early humans initially communicated through gestures, with spoken language evolving later.
Tool-Making Theory: Another theory proposes that the cognitive skills required for creating tools also contributed to the ability to structure thoughts into sentences.
Social Bonding/Gossiping Theory: Some experts believe speech evolved primarily as a mechanism to maintain bonds within large social groups. This theory posits that early forms of social grooming evolved into gossiping, serving to strengthen community ties and share common ideas.
Noam Chomsky's Innate Capacity: The renowned linguist Noam Chomsky argued that humans are born with an innate capacity for language, suggesting it is hardwired into the brain.

The prevailing view is that the truth likely lies in a combination of these theories, where factors such as social interaction (gossiping), cognitive development (tool use), and increasing brain size collectively contributed to language evolution.

Evidence from Archaeology and Anthropology

Beyond fossils and DNA, ancient works of art and tools provide invaluable clues about complex human behavior and language. These artifacts can be interpreted as "markers of identity," serving as ways for early humans to distinguish family, friends, and group members—much like wearing a specific sports team's shirt today. As communities grew larger, the need for such identification increased, potentially influencing the development of early words.

Researchers have observed that whales use unique songs as identifying names for themselves, suggesting a parallel possibility for early human language. It is hypothesized that the first human words might have served a similar purpose: a way to name ourselves.

Some experts believe that a very early form of language emerged with the first humans in East Africa. Notably, certain African languages feature clicks, a type of consonant sound rarely found in other languages. Some hypotheses suggest that these clicks might have been present in the earliest human languages.

Evolution and Diversity of Language

As humans dispersed across the globe, the variation in language grew significantly. Today, there are over 7,000 languages spoken worldwide. While not the earliest spoken languages, the oldest known written languages include Sumerian, Egyptian, and Akkadian. The oldest language still in continuous use today is believed to be Tamil, spoken in India, Sri Lanka, Malaysia, and Singapore. Chinese also boasts ancient linguistic roots.

The evolution of language is intrinsically linked to the increasing complexity of human society. It is likely that language evolved alongside societal advancements, including social interactions like coming-of-age rituals, fashion, and even table manners.

The Enduring Purpose of Language

Complex language is a completely unique and defining characteristic of being human. It empowers us with extraordinary capabilities: "Language allows us to tell stories and to dream and to fantasise. It allows us to time travel and talk about possible futures."

In the modern era, as society becomes increasingly digital, languages are changing faster than ever, with new slang, emojis, and terms emerging with each generation. However, the fundamental reason for human communication has remained constant: "To connect, share and be understood."

Synthesis/Conclusion

Human language is a sophisticated and unique phenomenon, underpinned by specific anatomical adaptations like the hyoid bone and genetic factors such as the FOXP2 gene. Its origins are likely a complex interplay of social needs, cognitive advancements, and an innate capacity for communication. Evidence from fossils, ancient DNA, and archaeological artifacts reveals its deep history and its role in identity formation and social cohesion. From the hypothesized early click languages in Africa to the over 7,000 diverse languages spoken globally today, language has continuously evolved. Despite rapid changes in the digital age, its core purpose—to connect, share, and enable understanding—remains the enduring foundation of human experience, allowing us to tell stories, dream, and envision possible futures.