Ad clicks are studied pretty extensively. A good search term is "compulsive clickers." The cariacature-with-a-bit-of-truth version is less-educated older white woman in Iowa. The heavy clicking user population, roughly 4% of users, is generally believed to contribute more than a majority of total clicks. This is as well-studied as you'd expect of clearly quantifiable data worth billions of dollars, and remains social…
By the way, the fact that you have to be mildly stupid or technologically illiterate to really be clicking on ads is the proverbial pink elephant in the room. To further extend this reasoning, building up stupidity and lessening tech literacy is actually functional to Facebook's and Google's business models.