“Instinctual” vs. “instinctive.”

Today, I heard someone on the radio use the word “instinctual.”  It’s another trendy word – we  hear it used more and more.  (See, also, “instinctually.”)

I looked it up.  “Instinctual,” alas, appears to be a legitimate word.  Several dictionaries suggest that “instinctual” and “instinctive” have the same meaning.  Others suggest subtle differences.  Frankly, it’s difficult to understand the distinctualization these sources are trying to present.

To me, “instinctual” just sounds more learned – read “haughty.”  Or, read “cool.”

Hence, I intuitually think one should use “instinctive.”  However, I’m totally down with one using “instinctual” if that one actually understands the difference.

Yet, perhaps the test should be this:  Does this person, who claims to understand the distinction, actually have both words in his personal vocabulary?