There is a difference between creative ability and creative skills. The former is an overall personal quality, while the latter are concrete capabilities. If you simply say you are creative, you are implying that in a fuzzy dichotomy of the creative and the uncreative, you have enough quanta of some sort of creativity points, and are thus decidedly creative. The perception of whether someone is creative or not is the same as the perception of whether someone is funny or not, or what-have-you; it is subjective and hard to define. (The research you mention about measuring human creativity baffles me entirely; the concept of measuring a subjective quality is nonsense to me.)
Now, you can demonstrate acts of creativity. From Wikipedia:
Creativity is a phenomenon whereby something new and valuable is created (such as an idea, a joke, an artistic or literary work, a painting or musical composition, a solution, an invention etc.).
If you have some creative skills which enable you to produce new and valuable things, you have a wonderful opportunity to list them on your resume/CV, or even display them. It is much easier to prove you have creative skills than to say you are generally creative. Whether a recruiter or hiring manager thinks you are have general creative ability is up to how much they read into your presentation of your creative skills.
jmac's example of Chris Spurlock's resume is a perfect example of how you can prove you have creative skills. If your creative skills are in the scope of or symbiotic with the type of work you are seeking, then you absolutely should use your resume/CV as an opportunity to prove this. Spurlock's resume proved his ability to create attractive graphical material, as well as competency with the web; both of these were directly related to his desired work.
Using myself as any example: I am by no means an artist (I am a software developer by trade), but I feel that I have an eye for good graphical presentation, and I can use some Adobe products, such as InDesign, with competency. Thus, I made my resume in InDesign and included some (basic) graphics to guide the eyes to the main sections of my resume. The atypical layout I used has caught some eyes which I really hoped would notice my resume; plus, when I list Photoshop and InDesign as supplementary skills, I have already provided some evidence of that. Whether or not a recruiter reads into the relative uniqueness of my resume as indicating that I am "creative" is moot, since it really does depend on the person reading the resume.
