tl;dr-ELT

I wonder if you’re familiar with Charles Hockett’s list of “design features of language”: arbitrariness, displacement, duality of patterning & so on. Developed in the 1960s, it’s a beautifully simple way of showing how human communication differs from animal systems & why language is so powerful. For instance, while a vervet monkey has a fixed call for “eagle”, humans can talk about an eagle from yesterday, compare it with a mythical phoenix or imagine one made of metal. For decades, this framework has felt solid, sensible & surprisingly durable. Many of us still encounter it when researching introductory linguistics or explaining what makes human language… well, human.

So I was intrigued by a new study reviewing 65 years of research across linguistics, cognitive science, anthropology & animal communication, which seems to indicate that several pillars of Hockett’s model don’t quite stand the test of time.

The study

Pleyer, Perlman, Lupyan, de Reus & Raviv (2025) revisited all 13 of Hockett’s original design features. Rather than running a single experiment, they conducted a large interdisciplinary review, drawing on evidence from sign languages, gesture studies, cross-species communication, cultural evolution experiments, language acquisition research & computational modelling. Their goal: to assess which features still hold, which need rethinking & what a modern picture of language looks like.

The findings

1. Language is deeply multimodal & semiotically diverse: Hockett assumed language = speech. Modern evidence shows that humans freely create languages in multiple modalities: visual (sign languages), tactile (such as [1]Tactile ASL), digital (emoji). Even spoken language relies heavily on gesture, prosody & facial expression to construct meaning.

Example: English speakers naturally slow their voice to depict something “slow” or raise pitch to express “very small”—that’s iconic meaning-making embedded in speech.

2. Language isn’t just a code; it’s inferential, social & cognitive: The authors argue that human communication is ostensive: we signal our intention to communicate, not merely encode & decode messages. We can “ask for coffee” by tilting a cup just as effectively as by speaking.

Language also acts as:

• a social signal (accents, registers & styles reveal group identity),
• a cognitive tool (labels shape categories & perception; children learn relations like “under” more easily once they have a word for them).

3. Language is an adaptive system shaped by interaction & cultural transmission Instead of fixed features, structure emerges through use. Cultural evolution studies show how iconic gestures become conventional, how grammatical patterns arise through repetition & how larger, more diverse communities develop more systematic grammars.

Patterns once thought uniquely human—combinatorial structure,[2] limited displacement—also appear in birds, primates & [3]insects. What seems unique is our ability to flexibly integrate multiple semiotic resources & turn almost any behaviour into an intentional communicative act.

Teacher Takeaways?

It’s a rather abstract study, but I’ll give it a go-

• Treat gesture, intonation & facial expression as central to language, not decorative. Integrating them helps learners communicate more naturally.
• Use iconicity deliberately: motivated forms can support vocabulary learning, especially for abstract concepts.
• Highlight identity, accent & register in class—language is always doing social work. Helping learners recognise this prepares them for real-world interaction.

How far does your teaching already reflect this richer, more multimodal view of what language is?

[1] Which involves reading signs by touching the hands, arms or body of the signer. It’s not a separate language, but rather a tactile version of an existing one (such as American Sign Language).

[2] the ability to communicate about things that are not in the here-and-now—past events, future possibilities, distant objects, hypothetical situations.

Humans have full displacement: We can talk about next Thursday’s meeting, yesterday’s storm, an imaginary planet or a person who doesn’t exist.

[3] For example, Honeybees can indicate the location of distant food sources via the waggle dance, but they can’t “discuss” new or fictional locations. Some other animals show small, constrained versions of human full displacement, hence limited displacement.