Does an object have "specificity to" or "specificity for" another object?

Question

Does an object possess specificity to or for another object? Every time I go to express this concept in writing, I struggle over which preposition is the more appropriate and more precise.

This is dilemma is encountered all the time in technical scientific writing, for example in biology where one speaks of enzymes with specificity to/for a particular substrate. I can't find much of a consensus there: I'm just as likely to see one form as the other in articles and published papers. My trusty Google consensus search isn't of much help either: the phrase "specificity to" occurs just about as often as the phrase "specificity for" does.

Although all of the examples I can think of at the time are biological in nature, I'm certain that there are others, so I'm asking this as a more general grammatical usage question. Do they mean something subtly different? Should one form always be preferred over the other?

Of course, it may be that either is entirely correct. Given that preposition usage is highly idiomatic in all languages (and English especially), there may not be a rule that definitively resolves this question.

Answer 1

I think the two versions have different meanings.

"For" implies a purpose for which something has been made specific, "to" implies a context in which a specific version exists.

The slang's specificity to that region was so extreme that people a hundred miles away couldn't understand it.

The design's specificity for the requirements meant it was unlikely to be adaptable for other users.

Of course, in many cases either would work:

The specificity of the orchid for its pollinator insect is astounding.

The specificity of the orchid to its pollinator insect is astounding.