No one can be an expert at everything, and so in some areas we are all laypeople (by layperson I means someone who has a general but not technical acquaintance with a subject). So the mistakes I point out here is not my way of laughing at the ignorant masses; since we are all laypeople some of the time we all make these mistakes occasionally. And so by realizing the mistakes we are prone to make we can learn to avoid them to some extent. Of course I have in mind here specifically science as understood by the public at large, but I suppose some of the same lessons carry over to philosophy and other subjects as well.
1: Not knowing what you don’t know
I admit that sounds like a tautology. But what I am trying to get at is that with only a general understanding of a subject there are details that not only we are ignorant of, but that we are unaware that we are ignorant of. Which means that when we try to apply what we know about the subject we may do so mistakenly, and, more importantly, be unaware of how we have made a mistake. A common example of this is people who say that relativity must be wrong because it is obvious that you can send signals faster than light by, for example, pushing and pulling a really long pole. Of course it is not actually possible to send signals faster than light in this way. But some are led to believe that it is possible because they don’t know that what they don’t know, in this case that how the pushing and pulling of objects works at an atomic level matters. Of course the lesson here is not to abandon trying to use what general information you know. However we should remember to be aware that when applying such general knowledge, especially when using it to come to our own conclusions, that we often make errors without realizing it. Thus it is foolish to treat conclusions we have reached in this way as reliable or authoritative.
2: Focus on anomalies
A second common mistake is to focus on anomalies, interesting events that are not yet explained by current theories, as extremely important and refuting the theory as a whole. First of all the fact that an anomaly has yet to be explained within the current theory doesn’t mean that it won’t be. Often what at first appears to be anomalous can be accounted for by some odd feature of the situation that is not usually taken into account when applying our scientific theories, or that we overlooked when first encountering the apparent anomaly. But of course there are real anomalies too. The existence of such anomalies does not mean that they are in principle unexplainable or that current theories should now be questioned or discarded. Admittedly an anomaly does mean that the theory in its current form is at least slightly wrong. But most anomalies prompt a revision of the theory in question, not an abandonment of it. What we sometimes forget as laypeople is that by the time a theory becomes known to laypeople it has such a large body of evidence in favor of it that one anomaly, or even a handful of anomalies, cannot trump. Nor do anomalies mean that the theory is now questionable and a matter of controversy in scientific circles. What leads to theories being abandoned, and what is a sign of real controversy, are scientists who have come up with competing theories that explain more facts, both the old facts and the anomalies, with more precision than the current theory. This is a very common mistake made by laypeople, who often latch onto anomalies as proof that the current scientific theories are wrong. In the long run usually they are right (every scientific theory is revised eventually), but theories are not replaced by the competitors laypeople often see them as having, but are instead replaced by revolutionary new theories (this is one of the mistakes made people who think that anomalies in the fossil record make intelligent design more likely; when evolution is superceded it will be by a theory with more predictive power, not less, and it will be a new theory, not an old one). If I may digress for a moment I think this focus on anomalies is caused by the tendency of people to see science as some kind of contest between the proponents of different theories, who win “points” against each other by pointing out flaws with each other’s theories. But that’s not how science works (sadly, that’s how philosophy seems to work sometimes).
3: Treating experts as biased / treating experts as idiots
And this brings us to our last, and most common, mistake, treating experts as though they weren’t experts. One way to make this mistake is to accuse the experts of being biased in favor of current theories (often in response to the fact that experts are not motivated by a few anomalies to reject established theories). Of course the experts are biased, but not in that way; they are biased in favor of their career. And being able to replace the currently established theories with new ones is a great way to further your career, and be remembered by future generations as well (Einstein, Darwin, etc). But, on the other hand, rejecting the established theories without good reason is a great way to kill your career. (Exception: when the expert in question is researching an anomaly, then they have a vested interest in making seem likely to overturn the established theories.) So generally you can trust the experts as to whether the established theories are still the best theories. (Of course you can’t trust them when it comes to their own research; there they will claim that they are always right, and making earthshaking discoveries, and deserve a grant.) Another expression of this mistake is thinking that you see some possibility unnoticed by scientists that, if true, completely invalidates some established theory (example: maybe cosmic microwave background radiation is caused by the atmosphere). The problem here is that experts spend much more time thinking about their discipline than we do. So if we can see a possibility so can they, and thus someone has already researched it and written a paper on it; it turned out not to be earthshaking and so it is never mentioned (we have made more precise measurements with space based telescopes). Of course the experts aren’t infallible, and they might have overlooked it, but it is generally best to assume that we haven’t outsmarted them.