HINOJOSA: And how they got there is the reason why the Kohn family is
now part of a national scientific study to locate a gene for
longevity.DR. TOM PERLS, CENTAGENETIX: We started off studying all the
centenarians in a region around Boston and found that they had several
things in common — for instance, they didn't smoke, very significant
obesity was rare. But beyond that we couldn't really pin our hat on
anything until we kept seeing a lot of brothers and sisters getting to
very old age. And some families where we're seeing many brothers and
sisters and cousins and parents getting to a very old age as well.
link: http://edition.cnn.com/TRANSCRIPTS/0109/01/stc.00.html
I guess the idiom "pin one's hat on" means something like "make a conclusion" or "be certain about".
I googled it but I couldn't find any meaningful resource.
What's the meaning of the idiom "pin one's hat on"?
Best Answer
You need something stable and firmly attached to your head, to 'pin your hat on'. In the case of the original hatpin, that was women's hair: the long pin was driven through the hat, then through the hair. More pins might also be used for greater stability.
In the figurative sense in your case, the thing the hat is pinned on is evidence [the hair] that supports analysis of or conclusions about factors contributing to comparative longevity [the hat].
Expectably, given your own failure to find information with Google, this idiom is not so common as I'd supposed from its immediate familiarity to me. Another instance of the same general meaning in use is this:
(From Inclusion Probabilities in Parentage Testing, American Association of Blood Banks, 1983.)
A third instance:
(From "Are human influences on the climate really small?".)
Perhaps diluting the sense of the 'pin one's hat on' idiom, two very similar idioms are frequently confused with it. The sense of one or another or both of the similar idioms is sometimes intended when 'pin one's hat on' is used. Those idioms are
A. hang one's hat on something;
B. pin one's hopes on something.
Their meanings are, respectively,
[From Cambridge Dictionary of American Idioms. S.v. "hang hat on." Retrieved February 16 2016 from http://idioms.thefreedictionary.com/hang+hat+on and The American Heritage Dictionary of Idioms by Christine Ammer. S.v. "pin one's hopes on." Retrieved February 16 2016 from http://idioms.thefreedictionary.com/pin+one%27s+hopes+on ]