When you think about it, it's "thinking" that sets us apart.
Who else but humans "think?" If "think" is what we mean when we process unimaginable and unnecessary brain synapses into sounds, pictures, re-arrangements of matter.
By reverse logic, we figure that there is a cognitive process when we express - or try to anyway - ourselves by making things. At the earliest age, we make sounds, the simplest - da da or ka ka - requiring no special effort. Pretty soon scrunched up little faces and personal sounds echo the gibberish that passes through our brain, and temper tantrums - like speaking louder to a deaf person - when these expressions don't have the effect we want.
Would we make words if we didn't already live in a world where everyone already has a vocabulary? I think we would. If words weren't there, we would be inventing them everyday.
My son never lets me forget the afternoon we had arrived at the beach house in Blanchisseuse, and after the first hour of unpacking and setting up, everyone else left for the beach as I sank into a deckchair, falling asleep on myself as I do. Son returns to find mama dozing, knees bent, feet tucked under. Mama tries to rise suddenly, buckles at the knees as cramp catches the calves. "What's up, Mom?" She stands and tries to stamp out the cramp. "Too-ghee..." What? "Too-gheeee..." blurted out as explanation of the feeling - cramp in the calves, wobbling at the knees, weak in the head? Tooghee to this day.
Just one more to add to the others that seem to have been invented - others might argue to be mere re-arrangements of sounds - in our islands. Words like bazoodee, or obzocky, or hassikara, or tootoolbay, or suck eye. (See Dictionary of the English/Creole of Trinidad and Tobago)
By this reasoning, words are invented everyday. Those that take become vocabulary. Let's consider "palancing" or more appropriately "we palancing!" Does this not express completely the state of the nation, the state of most Trinidadian lives, the lightness of being... Now, try to define it, or explain what it represents!