Human Stupidity: Historical: Memory

Our reasoning and our perception of the world are, as we have seen, far from perfect. While both of them do a good job in many of our every day tasks, they are subject to errors and it is not an overstatement to claim we should be wary of our own conclusions. This imperfection of our cognitive abilities can make us wonder if other functions of our brains suffer from similar problems.

While our emotions lie outside the scope of this work (it is already recognized we can suffer from all kinds of emotional diseases and there is no need to deal with that here), there is another function that we traditionally believe our brains perform well. That function is remembering. People tend to think of their memories as stored boxes they can consult at a later date, providing accurate descriptions of the facts we experienced in our own lives. It might be hard to find a specific memory sometimes and we do worry about forgetting, from simple information we can no longer recall to more serious pathologies where a patient memories can slowly be lost in a permanent way. All this fits well with the information in boxes metaphor, as one can eventually lose those boxes never to find them again. Or lose them for a while, until some new circumstances bring them back to our attention.

Most people, however, do not doubt the contents of their memory. If they do have a memory, unless they suffer from some delusional state, that means they believe things happened exactly they remember. And we trust our memories so completely that we send people to jail every day based only on witness testimonies, that is, on what people remember they saw or heard. And while a lawyer can defend a client by claiming the conditions of the perception of the witness were not good enough, no problem is usually detected on the ability to remember. That is, the legal system understand our perceptions can be flawed and should not be trusted, under the right circumstances. But it assumes that a healthy person will not create false memories or somehow alter the original ones.

This assumption tends to be considered true not just by the layman but also, until recently, by many psychologists. And, as a matter of fact, many practitioners believed (some still do) in the concept of "repressed memory''. That is, an event that a person has experienced in the past and have not really forgotten about. Instead, just the conscious memory is missing, as that event would probably have been very traumatic. Many therapists worked based on the idea that these memories can be recovered through treatment. And that, when these memories are indeed "recovered'', they correspond to actual events in the life of the patient.

The first indication that there was something wrong with this picture came from the unexpectedly large number of cases observed in the 90s where people claimed to have recovered "repressed memories'' of abuses they had suffered. What was particularly suspicious was the fact that the stories those people told often include elements that were supposed to be rare, as, for example, satanic practices. All those cases were recovered under particular types of psychotherapy and, as it should be if those memories were real, arrests and convictions did happen as consequence. The strange number of these cases did make a number of researchers worried that those memories, as vivid and real as they seemed to be to those who had recovered them, might actually be an artifact of the therapy.

Research followed, as it should. In a series of very interesting experiments, Elizabeth Loftus observed she could indeed create false memories in the mind of her subjects. Cases of people who had been wrongly found guilty were later observed, not only related to ``repressed memories'', but also in many cases where the evidence of guilt consisted of witness reports. Simple things like showing pictures of innocent people to a victim could cause that same victim to recognize, later, a man in those pictures as the man who had raped her. It is not clear how many innocent lives were destroyed due to our lack of understanding of how our minds work. Or how many real culprits were not identified by the same problem (for an explanation of the main results of this line of research, there is a very interesting TED lecture).

The image that emerged from those experiments is a different one when compared with previous beliefs. Our memory seems to be much more fluid than any of us would have thought. It is not just that we can suffer from problems with perception. As we learn more about some event, our brains actually change the very recording of that event, so that it will fit with our new beliefs. Missing pieces of information can be obtained from sources as unrelated to the event as a picture one observes later. What we carry in our minds is actually a mixture of what we observed, what we expected to see and things we have experienced or thought later, all mixed ("Memory - like liberty - is a fragile thing'', Elizabeth Loftus}.

In order to finish the topic of our memory, there is an interesting phrase by Steven Novella that he published while discussing the problem of the reliability of our memories in his blog:

"When someone looks at me and earnestly says, "I know what I saw,'' I am fond of replying, "No you don't.'' You have a distorted and constructed memory of a distorted and constructed perception, both of which are subservient to whatever narrative your brain is operating under." Extracted from here.

Human Stupidity: Historical: Visual Illusions

Almost everyone has seen pictures that deceive our eyes in some way. Some of them have two possible interpretations, others make us evaluate wrongly the size or the alignment of geometric figures. More complex figures can induce the illusion of movement when no actual movement is happening. And yet, illusion is a concept that is actually hard to define from a philosophical point of view, since it requires comparison with the true nature of the object, something we would tend to define as perceived by our senses. The number of different illusions and the way they work is actually so large that systematizing them into a few types or a theoretical framework has proved to be a surprisingly hard task.



The way our brain interprets the information it receives from our eyes can be considered similar to the way we reason. The task is indeed similar. Given what we know, the brain tries to arrive at the best possible conclusion. It uses heuristics and rules we still are starting to understand. These heuristics are usually good for solving some set of problems, either problems our ancestors had to deal with (get food, find a mate, etc.) or problems we learned to solve during our life time. The same way our brains have to deal with images. Given the visual information our eyes receive, our brain tries its best to interpret what exists in the world around us. It extrapolates and reaches conclusions that are not conscious, simply providing us with its best guess. And, most of the time, that guess is remarkably good.


Just as we discussed before, the fact we sometimes make mistakes of interpretation of visual information is not necessarily a bad thing for our survival. Recognition of patterns, whether those patterns emerge in the financial market or are the behaviour of the game one is hunting, is a very useful skill. And if one is the first to identify it, there is more to gain. This can be enough to compensate for the cost of false detections. And, indeed, in general reasoning as well as in interpreting visual information, we are able to identify patterns very fast, which leads to falsely identifying random meaningless noise with something important. This general phenomenon is called apophenia.


One interesting and helpful example of how this applies to our visual perception is our tendency to identify faces everywhere, from simple typographical juxtaposition of characters like :) or ;-( to seeing faces on rocks or on toasts or on shadowy, blurred images from Mars. This is called pareidolia. Quickly identifying other people as well as inferring their emotional state is certainly an useful trait for a social animal like humans are (see Demon-Haunted World: Science as a Candle in the Dark).


While this can be interesting and allows us to create new ways to communicate and to give extra meaning to some forms of art, the reality is that much of what we see as faces is a probably hard-wired conclusion of our brains. Indeed, evidence from MRI scanning of our brains show that the specific areas of the cortex that become more active when we see faces also show the same type of activity when we just perceive something as a face . The timing of the activity is also consistent with an early interpretation of the image as an actual face and not a later re-interpretation of the image by our brains. Amazingly, it is already possible to do neural reconstruction of the face someone is seeing from the detected pattern of the activity of the brain.

Human Stupidity: Historical: Heuristics II

Heuristics, in the context of the literature about human reasoning, is a fancier name for these rules of thumb. Before that, the term, based on a Greek word, was used by Pólya in his book How to Solve It, with the meaning of his methods (or advices) for solving mathematical problems. In that sense, he proposed a basic separation of four steps that he considered helpful in finding those solutions. While talking about human reasoning, however, heuristics is a simple rule (or rules) we use to guess an answer. Opposed to a mathematical proof, here, there is no guarantee the answer will be correct or good. Of course, Pólya's heuristics provide no certainty that you will arrive at an answer, they just intend to help your chances of finding it. If you do not make any mistakes, mathematics will make it sure you do get the right answer, then. While human reasoning heuristics will often give you an answer, even if not the correct one.

A classical example of how our heuristics can help us reason is the problem of trying to decide which of two cities has the biggest population. Gigerenzer and Goldstein performed a series of tests of possible procedures for guessing between two cities, when using a number of cues about the city, such as if the city had a soccer team in a major league or if the city had a university.
The researchers were interested in comparing how heuristic reasoning would compare against statistical models they considered as rational. They tested different methods for making predictions from the cues, namely, multiple regression and neural networks. To their surprise, even without using all the information, some of their simulated heuristics were often able to outperform the supposedly rational models where all the available information was used.

The "Take the best'' heuristic was particularly successful, despite its simplicity. It basically orders the cues from more informative to less and then uses the best one where information is available. The simulations included the possibility a simulated agent might not know enough to use the best cue available, forcing the agent to check the next cue. As soon as one cue provides any evidence to which city might be the biggest, "Take the best'' uses that cue and just ignore any information from the other cues.

We observe here an effect that seems similar to how humans accuracy decreases with more information. However, we can not actually make that claim, since we don't know the exact reason for the human mistakes. In the case of multiple regression models, on the other hand, the reason is clear. While it is quite surprising at first that using less information might be better when using a statistical model, it is a known problem that statistical models that use many variables can overfit the data. This phenomenon will be further discussed later, when we discuss inductive logic and the use of probabilistic models. We will see how good prediction requires the use of models that both fit the data well and are as simple as possible.

Human Stupidity: Historical: Heuristics

Humans are considered (by humans) as the most intelligent species known (to mankind). And, when we observe how much we have been able to accomplish as a species and compare that to every other species on Earth, that statement makes a lot of sense. One could debate if some big brained animals might be individually as intelligent as an individual human (he question now seems far less absurd than decades ago, as we learn more and more about the abilities of some animals and our own shortcomings). But there is no denying that what we have achieved as a species is without precedents. We have vehicles exploring the deep ocean and other planets, while others are leaving the Solar System; we can communicate almost instantaneously around our world and we understand the world around us in ways that a few generations ago wouldn't even dream. We have been changing the appearance of our planet (for good and also for evil) in a scale not done by an any organism, probably since the appearance of the first plants that could photosynthesize (The oxygen they started producing, while vital for us, was certainly a pollution for most organisms that lived then and must have caused widespread death among the species that didn't adapt to the new environment, much like the widespread death we are causing. Polluting and killing is not our exclusivity at all). And, for the first time since life started on Earth, we have been able to subvert most of the survival rules that apply to other species, changing how evolution applies to us by making it possible for even the some of the weakest among our species to survive and reach an old age, safe from the dangerous and fatal natural environment.

Those are very impressive accomplishments and they do give us the sense that, while we are far from perfect, or even far from good enough, we have been able to do something right. Culturally, we even see ourselves as something apart from the natural world, as if we were somehow superior to nature and not just a very successful species of big apes. While the distinction between natural and artificial makes no sense (one might be tempted to say it is completely artificial), it does reflect the fact that we have, in the local scale, subverted the relation we have with the world around us. And, while there are many reasons to worry about the future, our present is actually almost unbelievably better than we our perception of it. Violent deaths have never been so rare, humans never lived such long lives, all due to the advances in science and in our cultural and political institutions as shown recently by Pinker. The data that show this to be a fact are not so hard to find and we only feel we are surrounded by violence and disasters as an effect of the news focusing on those events. And, since information circulates much better now, we can learn about almost any disaster in the planet. With billions alive, the total number of crimes and disasters is indeed large. Not only we can learn about natural disasters happening at the other side of the globe, now it is very likely that there are people living there who will be affected by it. But what really matters to any of us as individuals is the proportion of people who die or who suffer, not the total number that happens in a larger population and, much less, the total number of cases we can find in the Internet. What matters is the probability that a given tragedy will affect one person. And these probabilities have been steadily going down (with the important exception of the ills associated with old age, as, in the old days, they were quite rare, since basically nobody reached old age), to the point that, even without ever seeing the data, I would personally bet that the life expectation of an Egyptian pharaoh was much smaller than that of a poor and discriminated person, as, per example, a black poor woman living in a crime infested slum in Brazil. That this statement can be surprising to so many is just a consequence of the many problems with our reasoning.

So, what is actually happening? Are we completely stupid incompetents or are we incredible geniuses who mastered the secrets of the Universe and changed the world into a utopia? The answer is clearly that we are neither, even though there is some truth to the notion that we are very dumb and also to the notion that we are actually living in a Golden Age of mankind.

One first partial answer to the question of how we (or any other living being) can actually achieve so much while being quite dumb was suggested by Simon, in 1956. In his paper, Simon investigated if it was actually necessary for a living organism to have a well defined utility function as proposed by the EUT, as well as the intellectual capacity to analyze its environment and make the decisions that maximize that utility. Organisms need to find ways to deal with a multitude of different tasks, from feeding, to defending itself and reproducing if the species is to survive. Actually obtaining and interpreting all available data from observing its surroundings and choosing the best way to obtain the best possible outcome, when all those tasks are considered, is basically an impossible problem. It would require a mental capacity far beyond the one we possess and this basically infinite capacity would also need to happen very fast. You really don't want to sit and think what is the best choice when a lion is closing to you. Since finding the perfect answer is not achievable, organisms had to settle for less.

Assume there are a number of clues in the environment that you could use in a simple way to make some decision. If this decision will give you a better chance to survive than not using those clues, any organism that uses those clues will have an advantage when compared to organisms who don't (as long as processing this information does not consume so much energy that the benefit is smaller than the cost, of course). So, an organism does not need to find the optimum, or, in economic terms, to optimize its utility. It can actually function competently by finding efficient, but not necessarily error-proof, ways to interpret the information captured by its senses. Simon describing this non-optimal behavior as satisficing (Evolution does not requires any species to be the best to survive. Being better than the others would be sufficient, but even being better might not be a good strategy. The real concept is better adapted. Not stronger, or faster, or smarter, sometimes, being weaker can actually mean better adapted. In an environment with scarce resources, being too big and strong might require extra food that is not available. In this case, the weaker organisms, who are able to survive with less, are the best adapted to that environment. This applies to strength, but also to speed, to mental prowess or any other characteristic.).

That is, if simple rules of thumb make you more likely to survive, it makes sense to use them. Per example, if you are looking for the cause of a phenomenon, it makes sense to look for things that happen together with it. After all, if it is the cause, you do expect those things to be related. The fact that many variables can be associated with no causal connection means you will often believe that things are related when they are not.

Suppose you are belong to a family of farmers without any of our modern knowledge. You try to plant your seeds and sometimes things go well and the climate seems to be working in your favor. At other times, it gets cold too soon, or there is not enough water for your plants to grow. After a long time observing, your grandfather observed if he planted the seeds whenever a specific bright star appeared low on the sky just when the Sun went down, the climate would be right for the plant to grow. Your parents confirmed it as well as your own experience. So, you conclude that this star commands the success of your farming. While this conclusion is wrong, there is no cause there, the observation of movement of the stars is indeed associated with the calendar and the seasons. And your decision will indeed be better. If you extend the argument to the belief that the same star will influence the chance of your success in war, you will be very wrong. But, without better information, there is no way you can actually determine the better day to go to war. Going when you believe the stars support you is a costless mistake, from an evolutionary point of view, since it does not improve or decreases your chance of success.

Mistaking association for cause is indeed an incredibly common mistake. My own personal experience with association and causation is actually quite worrisome. I am used to telling my students that their exams are very likely to include a question where variables will be associated and I will ask about causes. And I make it abundantly clear, with examples and theory, that observational studies (I will define these later in this text), one can not conclude that there is cause and effect. And yet, a large percentage of these students make this very same mistake during the exams (of course, this might be related to the fact that I tell my students that, if they do not show up for class but succeed at the exam, I will give them the minimum required attendance, so it is possible that the students who make that mistake were not at those three or four classes when I tell them one of the exam questions. But my best guess is that it is not just that). Outside of the exams, this can be a low cost mistake, so, it is a reasonable rule of thumb, despite the fact that is is logically wrong.

Human Stupidity: Historical: Control Issues

Besides all the errors we have seen so far, humans seem to have an innate ability to believe they are in control, even when that is not true, nor even possible. In 1975, Langer and Roth tested people on whether they felt they would be able to predict the outcome of random coin tosses. They rigged the outcome in such way that all participants would get the same number of correct guesses. The main difference was that the order of the correct outcomes was different, with three groups. For some of the subjects, those correct predictions would happen more often at their first attempts; the second group experienced a stable rate of success; and the third group started getting more wrong answers at first and more correct ones at the end. Consistent with the primacy effect, those who had obtained their correct answers sooner considered themselves more skilled than those who had observed more correct answers later. That was despite the fact the percentage of hits was the same for all involved. The confidence on their skills was not related with how successful they had been in the overall task, but just with how well they had performed in the beginning.

However, not everyone who participated in the experiment was asked to make predictions. A number of people were just instructed to observe the ones who were making the predictions and evaluate their skill at the task. Those who just observed evaluated the overall skill of the guessers as worse than the guessers evaluated themselves. Being in control had an effect on how people seemed to report the skill.

Interestingly, despite being clear the subjects had no influence on the outcome, those people who felt they were more skilled at predicting the outcomes would, after a while, start attributing their correct answers to their ability, while the wrong ones were blamed on chance (Anyone who has taught courses and graded the exams of their students can probably observe this effect. Many students seem to honestly (and absurdly) believe  in the combination that any success in the classroom is due to their merit, while failures are to blame on the teacher, or study conditions, anything but themselves). And their false belief in their merit extend to how they evaluated different aspects of the problem. Both guessers and observers assumed that, if the guesser had the opportunity to train for that task, he would improve his performance. And they seriously felt that the existence of distractions would cause them to obtain a smaller number of correct results.

This illusion that we have some degree of control even when the task is completely random has been observed in several different tasks since these results. Pronin et al observed how this illusion of control is related to magical thinking, by making people actually believe that they have harmed others through a voodoo hex, especially when they have harboured evil thoughts about the victim or that they could influence the outcome of a basketball game by positive visualizations of their success (t should be unnecessary to say both effects are completely false, but unfortunately, this comment is very much needed). And, while failure at predicting sport events might be, for most people (except, of course, for betters), the same illusion can serious consequences in other areas. Some of those consequences might even be positive, since being in control can be related with feeling better. But this can also lead to bad decisions in all areas of human enterprise. For example, Odean discusses the consequences on the behaviour of prices of the fact traders are overconfident about their abilities and the control they actually have on the outcome of their investments. And I have often observed (and I am sure most readers have also) how people believe that their actions, sometimes just their intent, would actually influence outcomes that are mostly random.

But do not despair yet, dear reader. While the number of studies that show our mistakes is staggering, I believe I have been able to convince many of you of how we can not trust our own intuitions(and such a belief is almost certainly my own illusion of control that I have more influence on how you think than I actually have). As such, we will proceed now to more optimistic waters, first taking a cursory view on the explanations of why it is possible that we are so incompetent (we are not really incompetent, we are just far less competent than we would like to believe). And later ahead, we will ask the important question of how we can actually do better and try to avoid the many pitfalls our brains have in store for us.

Human Stupidity: Historical: Calibration

The question of how well a person knows her real chance to get an answer right is called calibration. In general terms, a person who is 95% sure he got the correct answer, is expected to be correct 95% of the times. If he only answers correctly 70% of those questions, we can say that this person is not well calibrated on how well he knows what he knows. However, for one given question and one specific person, the answer will either be right or wrong. That means that some caution must be taken when measuring actual accuracy. Different studies can actually provide different answers depending on how the term is actually defined. This means that some discrepancy in the results and the explanations given by each author is to be expected. And, while that is indeed the case, the amount of evidence on the existence of problems with how well calibrated we tend to be is very strong.


An important question is, therefore, when should we expect to observe problems in calibration and when not. Griffin and Tversky (or also Chapter 13 in Heuristics and Biases: The Psychology of Intuitive Judgment) observed in 1992 that people seem to account wrongly for different statistical information that they call weight and strength of the evidence (personally, I find this terminology confusing, as the statistical meaning of the terms is not very clear from the names. But it is a standard way of speaking in the area) Basically, the strength of the evidence would be the proportion that was observed and the weight, the size of the sample. That is, if you toss a biased coin 20 times and obtains 16 heads, the strength of the observation is the fact that you observed heads 80% of the times, while the weight of the evidence is the fact that this was observed over 20 tosses. Both pieces of information must be used in any attempt to predict whether the coin is actually biased towards heads, as well as how likely it is that we would get heads if we toss the coin once more. However, what Griffin and Tversky observed was that, while basically accounting correctly for the observed proportion (strength), people did not take into account the weight of the data (sample size) correctly.


Quite interestingly enough, they comment, among other things, on the the problem of ``illusion of validity'', term coined by Kahneman and Tversky in 1973 (also in Chapter 4 in Judgment under Uncertainty: Heuristics and Biases This effect can be described as the fact that different questions produce different measurements of calibration. More exactly, what was observed was that people have a tendency to be more overconfident about individual cases than about their overall accuracy. For example, Cooper et al, while interviewing almost 3,000 entrepreneurs, observed that they were widely overconfident about the chance of success of their own business. On the other hand, when asked about the chance of success of a generic enterprise in their area, that overconfidence was much smaller and they proved to be just moderately overconfident. This is something that would actually be expected, due to an observation bias effect. Even if there was no average overconfidence among people on the success of businesses, some amount of random error would be unavoidable. That is, any entrepreneur was was well calibrated, in average, could show some overconfidence in some of the business area and underconfidence in others. Of course, entrepreneurs who evaluated an area as more likely to succeed would be expect to invest more in that area. And this overconfidence was not associated with those who were better prepared or actually had a better chance to succeed than their competition. What they observed was the poorly prepared entrepreneurs showed the same optimism than the better prepared ones (perhaps another example of the curse of the incompetent).


But not only calibration problems are dependent on what people are trying to answer, they are also not observed in every situation. Actually, Lichtenstein and Fischhoff observed that people can be trained. In an experiment where people had to distinguish if one phrase had been handwritten by and American or an European, they observed that, simply by providing a basic initial training, their subjects not only got more questions correctly, but also showed a better calibration about their evaluations. In his book The Psychology of Judgment and Decision Making (McGraw-Hill Series in Social Psychology), Plous reviews and compares the results of studies of calibration in two different areas, one in predicting meteorological events, by Murphy and Winkler and the other about physicians estimating the probability of a given patient to have pneumonia, by Christensen-Szalansk and Busyhead. And, contrary to popular culture assessments, the meteorologists proved to be quite well calibrated, while the physicians showed an absurd amount of overconfidence. An important part of what seems to be happening is that meteorologists get much more feedback about the accuracy of their predictions than physicians do. As a matter of fact, Lichtenstein and Fischhoff , in another study,
observed that, after some training where they provided feedback on how accurate people were on their answers, almost all their subjects improved their calibration. The exception was, actually, the few individuals who were already well calibrated before the training. This seems to make it clear the incredible importance of getting feedback on how precise one predictions were.

TED Talks on Irrationality

I just found a very interesting series of videos from the TED Talks people. It is a playlist entitled "Our brains: predictably irrational".

I haven't  watched any of those yet, but they certainly are in my to do list. I hope we all enjoy it.