Does sugar make kids hyper? Has science proven bumble bees can’t fly? Does the average person only use 10% of their brain capacity? Are routine multivitamins good for you? Were the dinosaurs killed off by an asteroid impact?

It is often observed that when a fact is accepted uncritically because, “everyone knows it to be true,” it is probably false. The answers to the above questions are no, no, no, probably not, and it’s more complicated than you think.

The best way to drive this home for many people is this – think of the one area of knowledge in which you have the greatest expertise. This does not have to be your job, it can be just a hobby. Now, how accurate are news reports that deal with your area of extensive knowledge? How much does the average person know? Does anyone other than a fellow enthusiast or expert ever get it quite right?

The universal experience (according to my informal survey over many years) is that the general public is full of misinformation and oversimplifications about your area of knowledge. Now extrapolate that experience to all other areas of knowledge. This means that you are full of misinformation and oversimplifications about every area in which you are not an expert.

Further, it is difficult to appreciate your own level of ignorance on a topic about which you are ignorant. The Dunning-Kruger effect applies to everyone.

This realization should have a humbling effect. It should also have a motivating effect, to always dig a little deeper and not be content with superficial absorbed knowledge.

One question that emerges from this realization is – why? To answer this, first let me dispense with the false dichotomy of “right” and “wrong.” Some answers are simply right or wrong, but they are at the extremes of a continuum. Many answers are partly right, or right to a certain extent but the truth is more complicated. Some answers are not so much wrong as incomplete. The desire to say that something is right or wrong sometimes gets in the way of exploring the true nature of the answer.

For example, is it wrong to say that the Earth revolves about the sun? As far as that statement goes, it is essentially true. It is true enough for some purposes, such as having a basic concept of how the universe is put together.

However, the statement is not strictly true. The Earth and sun both revolve about their mutual center of gravity. That center of gravity point, however, lies beneath the surface of the sun, and so it is reasonable to say the Earth revolves about the sun, while the sun just wobbles as a result.

Is it correct to say that the dinosaurs were wiped out by an asteroid? This is a reasonable first approximation of the current scientific consensus. However, a scientific pedant would point out that birds are dinosaurs, and so what you really mean is that the non-avian dinosaurs were wiped out. Further, there is a viable alternate scientific opinion that volcanic activity contributed to, and may have even been a primary cause of, the mass extinction.

And even that is a massive oversimplification summarizing a complex scientific debate. How deep do you want to go?

Another way to look at it is this – there is a grade school answer, a high school answer, a college undergraduate answer, an expert answer, and an international thought-leader answer. The goal for anyone who wants to be right should therefore be to be correct enough at your level of understanding, but to appreciate that there are deeper levels, and to be pushing toward the next level deeper of understanding. Be humble and curious.

But we still have not addressed the question of why most common knowledge is more inaccurate than it should be (often to the point of being wrong). That is a complex question, but here is my attempt at a quick summary. It partly derives from human psychology, and partly from culture.

People have a desire for simplicity and control. This motivates them to boil down complex knowledge into bite-sized nuggets. This necessarily introduces inaccuracy. Further, reality is horrifically complex. A good rule of thumb is – it’s always more complicated than you think.

People have limited time and mental energy. Any one person can only ever scratch the surface of even existing human knowledge, and that knowledge is exploding. So we have to take shortcuts, oversimplify, and settle for decent approximations. Just don’t fool yourself into thinking this is definitive knowledge, or ignore the vast depth of knowledge that you don’t have. If you are going to settle for good enough, then be realistic about what that means.

This is why I think it is a good idea for everyone to strive to have at least one area of very deep knowledge. It could be anything, whatever strikes your fancy. This teaches you about the structure and depth of knowledge itself. At the same time I think it is helpful to have a breadth of knowledge. It’s interesting to think about what the optimal pattern of knowledge is. I strive to have a basic understanding of everything, with areas of varying degrees of interest and expertise.

Culture also plays a huge role. Bits of knowledge (some might call them “memes”) spread through culture, and it is interesting to contemplate which memes survive and thrive. I do think there are selective pressures involved, and they seem to favor ideas and “facts” that speak to us in some way, that resonate, or reflect some fundamental idea, hope, or emotion. They don’t seem to favor accuracy and precision.

We love stories that are ironic, or are iconic of a belief, hope, or even fear. Sometimes they rise to the level of urban legends, but these are just the extreme examples. This is what filters down to the public consciousness. We might call this passive knowledge. It is what comes to you through your social network (which has now been vastly increased through both traditional and now social media).

A good rule of thumb is to be suspicious of all passive knowledge, for the reasons I stated above. You need to follow up with active knowledge, looking for reliable sources for confirmation and analysis.

Conclusion

The end result of psychological and cultural factors is that most of the common knowledge floating around is highly inaccurate or misleading, often to the point of being simply wrong.

Appreciating this situation is helpful and even empowering. The adaptive reaction to this realization is to be humble before the depth of your own ignorance. To be suspicious of all passive knowledge. To be aware of your own psychological biases. And to be curious enough to seek more accurate and deeper knowledge.

You might summarize all of this by saying – be skeptical.