If there are two aspects that differentiate homo-sapiens from other species, most people would agree they’re man’s prehensile thumb and his sophisticated use of language. But what is it about language that really shows us what it means to be human?

There’s a small tribe of Amazonian Indians, the Piraha, who’ve lived along Brazil’s Maici River for as long as anyone can remember. Their language teaches us a lot about the relationship between language and culture. And, perhaps more importantly, shows us how language evolved to capture one of our most essential aspects of humanity: universal kinship.

Most languages have a huge array of kinship terms. Let’s take English for example: parent, father, mother, grandmother, grandfather, aunt, uncle, great aunt, great uncle, daughter, son, step-daughter, step-son, step-mother, step-father, paternal grandmother, maternal grandfather, first-second-third-cousin, cousin once removed, nephew, niece, oldest nephew…you get the picture.

In Piraha (pronounced pee-da-HAN) there are only five kinship terms:

• baixi – parent, grandparent, or used when indicating deference to anyone
• hoagie or hoisai – son
• kai – daughter
• piihi – child with at least one deceased parent, stepchild, or favorite child
• xahaigi – sibling

This last term, xahaigi, has all sorts of meanings. It may also be the most common term since it crosses gender, generational, and, most importantly, family boundaries. “Sibling” is a name that’s used by all members of the Pirahan community. Author and linguist Daniel Everett explains the concept of xahaigi in his book Don’t Sleep, There are Snakes:

“(The word) seems to express more than kinship. It expresses a value of community. Because this word is genderless and numberless, it can refer to a man, a woman, women, men, or a mixed group…there is a strong sense of community and mutual responsibility for the well-being of community members”

(D. Everett, 2008, p. 86-87).

It’s probably no coincidence that the Piraha care for all members of the group without bias…children, the elderly, everyone.

People often ask me for specific examples of the language-culture connection. I can’t think of a stronger illustration than that of the Piraha word for “sibling” and its widespread use within the community as a whole. You’ll sometimes hear a linguist saying that rich, or advanced, languages are those with tremendously vast vocabularies. It’s as if the quantity of words indicates the richness of a language. They look at the number of words as a means for measuring how “advanced” a language is. (And since language and culture are so intricately connected, would this mean by implication that it’s a measure of an “advanced” culture as well?) I would argue differently.

Let’s look at the international response to Japan’s recent catastrophe. The Japan tsunami was a calamity beyond description. (I’m not sure there’s a word in any language that can do justice to how tragic this was/is.) People from all over the globe, regardless of race, religion, political perspective, and even history (take China, for example), reached out to help. If the meaning of the term ‘sibling’ means being connected to each member of society…taking care of and being taken care of…how much more advanced can you get? I’d warn against getting stuck in too rigid of a definition of what makes a language advanced. Perhaps the most effective antidote would be to think of language as a reflection of its culture, not just as a means of getting a point across. What we might just find, in some way or another, is that we’re all xahaigi.