"a certain proclivity" is correct and usable in written English.
It is usually used to describe something that a person has a strong inclination or tendency to do. For example, "Jason had a certain proclivity for taking risks that often paid off."
It is expected to be a protracted struggle in a country whose traditions include fractious tribes, a certain proclivity for radical Islam and the kind of widespread poverty that can help breed extremism.
Several of the scientists interviewed admitted that they simply were not cut out to do extensional, incremental science; they bored too easily, they said, which suggests a certain proclivity toward scientific risk.
Although it certainly seems like McCollum has a certain proclivity for exhibitionism on bus benches.
A certain "weird proclivity for intuitive math" meant, moreover, that he found the "geometric thinking" required by tennis (all those rapid trigonometric calculations) straightforward.
For people of a certain technological proclivity, this has become the new multitasking: to live simultaneously in the physical world and in their smartphones, without missing out on either.
The kind of magical nanny that, when the door swings open, might declare, in a headmistressy voice: "I hear you've been NAUGHTY" in a way that could make a good many people of a certain fetishistic proclivity become quite excited.
"People are born with an inherent predisposition for certain proclivities; this innate potential for atypical sexualities and fetishes may or may not be expressed.
And like any social media site, certain members become known for certain proclivities, which brings us to a Fetlife member known as Jilf.
In keeping with Wurm's tongue-in-cheek approach to formalism, and his proclivity for a certain shade of pink that democratizes his miscellany of creations, the sculpture is attired in a proper New York trench coat and its arms and head have been subsumed into a solid block of an abdomen, somewhat mirroring the hotel's own rectilinear silhouette, but also bringing to mind a giant Popsicle.
Guidry also happened to be the Yankees' money starting pitcher, and his proclivity for pregame exploits in the outfield grated on a certain owner.
