Uncertainties
There is ambiguity about several facets of the false-consensus effect, as well as its study. First of all, it is unclear exactly which factors play the largest role in the strength and prevalence of the false-consensus effect in individuals (ex: Two individuals in the same group and with very similar social standing could have very different levels of FCE, but it is unclear what social, personality or perceptual differences between them play the largest role in causing this disparity).
Additionally, it can be difficult to obtain accurate survey data about the FCE (as well as other psychological biases) because the search for consistent, reliable groups to be surveyed (often over an extended period of time) often leads to groups that might have dynamics slightly different from those of the "real world." For example, many of the referenced studies in this article examined college students, who might have an especially high level of FCE both because they are surrounded by their peers (and perhaps experience the availability heuristic) and because they often assume they are similar to their peers. This may result in distorted data from some studies of the false-consensus effect.
Read more about this topic: False-consensus Effect