Is it ACHA or AHCA? A linguist explains why so many people are abbreviating the healthcare bill wrong

As Congress geared up for a vote on the American Health Care Act on Friday before the bill was pulled, one thing was for certain: folks were having a difficult time abbreviating its title.

All over social media, journalists, pundits, and even some of the very politicians voting on the healthcare bill have mistakenly referred to it with the acronym "ACHA," instead of the seemingly correct "AHCA."

But these mistaken acronyms are more than just a case of coincidental typos. As New York University linguist Lisa Davidson explained, there's a perfectly scientific reason why this acronym in particular seems to be dogging so many people.

As Davidson explained, it comes down to how often certain combinations of letters appear in English words - or "orthographic frequency," in linguistic terms.

"The spelling 'CH' is extremely common," Davidson told Business Insider. "We're spelling that all the time. So when we go to type something or write something, that's a natural thing to come up with."

A look at the dictionary clarifies her point. The cluster "ch" makes an appearance in thousands of English words - choice, rich, and teach, just to name a few. Meanwhile, the sequence "hc" is considerably more obscure - those letters almost never appear together at all, save a few obscure compound words like "pushcart" or "fishcake." (Perhaps ironically, they do show up side-by-side in the middle of the word "healthcare.")

When we come across an acronym like AHCA, our brain naturally interprets it as the more plausible series of letters, resulting in ACHAs across the keyboard.

"'AHCA' is definitely not something that we ever type, and it's not something we ever see spelled," Davidson told Business Insider. "So if we see the acronym we are very unlikely to retain the 'HC' in memory."

"Our muscle memory would never have us typing 'HC' because we never see that in English."

In the case of AHCA vs. ACHA, our brains are seeing something that's just not there.