MBTI = junk science?

One of the most commonly cited reasons why MBTI is regarded as “junk science” is that it has failed to pass double-blind testing. A double-blind experiment means that neither the participants nor the researchers know which group anyone belongs to during the trial, thereby minimizing bias and serving as a basic standard of scientific validation. However, to say that the absence of double-blind testing is the whole problem is to oversimplify the issue. Double-blind trials alone cannot be the measure by which all bodies of knowledge are judged.

A clear example of this can be found when comparing traditional Eastern medicine and Western medicine. Traditional medicine has, over thousands of years, accumulated clinical experience and inductive data that show certain effects. The theoretical framework behind it—such as the Five Phases (yin-yang and the five elements), which attempts to explain phenomena through causal treatment rather than mere symptomatic relief—is crude and scientifically weak, yet some of the treatments derived from it have been observed to produce genuine efficacy. In other words, what may not be captured in short-term controlled experiments can sometimes be confirmed through long-term accumulation of experience. In fact, over time Western medicine has re-examined and officially adopted certain treatments that originated in Eastern practice. From another perspective, one could even argue that the East arrived at certain therapeutic discoveries earlier than the West.

Even if we set aside the rigid adherence to double-blind methodology, MBTI still cannot escape the label of junk science. Why is that? Or do you believe MBTI is actually trustworthy?