The Problem with "Self-Report" assesments

One of the primary issues, and frankly, the Achilles heel of all of these personality theories, is that they rely almost entirely on self-report assessments.

A researcher or a theorist will come along and decide what sort of questions to ask in order to get the respondent to start sifting themselves into one category or another. This is nothing new, we have been asking people “how they feel” about things long before modern Psychology was even a thing. Its more efficient to do it this way, just let people tell you how they feel about this or that, and trust that they’re telling you the truth. The alternative to self-report would likely be long, drawn out observations of a subject. There would be no anonymity, no scaling of data collection, and would be insanely expensive.