Does your head feel heavy?

Slate's Jon Cohen has a thoughtful piece about the profound differences between man and ape, and why never the twain shall meet ― Hollywood notwithstanding. Apart from the fact that we separated from a common ancestor with chimpanzees some 5 million years ago, humans are hardwired for language. Our knuckle-dragging relatives are not. Cohen notes our ability to "acquire massive vocabularies (we typically have 60,000 words by high-school age)." Given that amount of tonnage, it's a wonder we can lift our heads at all. Where, I wondered, did that 60K figure come from anyway? Is that really the average size of a person’s vocabulary? Linguist and dictionary expert Michael Quinion says asking is easy. Answering it is anything but. "[It] all depends what you mean by word and by vocabulary (or even English)," he writes. Long story short: Your average Napoleon Dynamite teenager probably has a vocabulary of 10,000-12,000 words. College grads have somewhere between 20,000 and 60,000 words. But that just covers active words. Passive words tend to be severely underestimated, Quinion says. Further complicating matters, lifestyle, profession and hobby interests also influence the number of words you carry around in your head. Anyway, this is definitely the stuff of No. 10 headaches. I'm almost sorry I asked.

(Art credit: "Heavy Headed Limbo" by Andrea L Cornish)