Search Results for "bias"

May 06 2013

The Lunar Effect and Confirmation Bias

I gave a seminar recently to science teachers and the topic of whether or not there is a lunar effect came up. I was not surprised to find that 80% of them believed that emergency rooms and police stations are more busy during a full moon. I was also not surprised, but only because I have been there before, that they were highly resistant to my claim that the scientific evidence shows that there is no such effect.

Several questions emerge from the notion that the phases of the moon affect human behavior: what is the plausibility of such a claim, is there actually such an effect, and if not why do so many people believe that there is?


One of two justifications are commonly given for how the moon might influence human behavior. The moon basically has two physical effects on our environment – gravity and light. Astrological influences are not worth further discussion in this article, and I rarely hear that as a justification from the general public in any case.

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Dec 04 2012

The Power of Confirmation Bias

It is my contention that scientific skepticism is an intellectual discipline and a cognitive skill set more than anything else. It is also a philosophy, a value system, and an approach to knowledge – but these are hollow without the knowledge and skills to apply that philosophy.

This is especially true in our complex world, with sophisticated pseudoscience alongside mature and highly technical real science, ideologies of every stripe pushing their agenda, governments with power to protect, and markets and corporations with a profit motive to deceive. The internet is also drowning us in information, much of it dodgy.

It is therefore not enough to have a generally skeptical outlook, or even to call oneself a skeptic. Skepticism is a journey of self-knowledge, exploration, and mastering the various skills that comprise so-called metacognition – the ability to think about thinking. <shameless plug> For a thorough discussion of metacogntion, you can check out my Teaching Company course: Your Deceptive Mind: A Scientific Guide to Critical Thinking Skills. I also understand it makes a wonderful gift.</shameless plug>

As an example of the need for metacognitive skills in navigating this complex world there is confirmation bias. This is definitely on my top 5 list of core skeptical concepts, and is a major contributor to faulty thinking. Confirmation bias is the tendency to perceive and accept information that seems to confirm our existing beliefs, while ignoring, forgetting, or explaining away information that contradicts our existing beliefs. It is a systematic bias that works relentlessly and often subtly to push us in the direction of a desired or preexisting conclusion or bias. Worse – it gives us a false sense of confidence in that conclusion. We think we are following the evidence, when in fact we are leading the evidence.

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Mar 29 2012

Perception and Publication Bias

The psychological literature is full of studies that demonstrate that our biases affect our perception of the world. In fact psychologists have defined many specific biases that affect not only how we see but how we think about the world. Confirmation bias, for example, is the tendency to notice, accept, and remember data that confirms what we already believe, and to ignore, forget, or explain away data that is contradictory to our beliefs.

Balcetis and Dunning have published a series of five studies that add to this literature by showing what they call “wishful seeing.” In their studies they found that people perceive desirable items as being physically closer to them than less desirable items. This finding is plausible and easy to believe for a skeptic steeped in knowledge of cognitive flaws and biases. But is this finding itself reliable? Psychologists familiar with the history of this question might note that similar ideas were researched in the 1950s and ultimately rejected. But that aside, can we analyze the data from Balcetis and Dunning and make conclusions about how reliable it is?

Recently Gregory Francis did just that, revealing an interesting aspect of the “wishful seeing” data that calls it into question. ¬†Ironically the fact that Balcetis and Dunning published the results of five studies may have weakened their data rather than strengthen it. The reason is publication bias.

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Mar 18 2011

Biases in Science Fiction

Published by under General

I woke up with a strange idea in my head that I wanted to get off my chest. This has to do with how we project our biases onto fiction, in this case specifically science fiction. My thought involves ship design – how would you design a ship for deep space travel?

First let’s take some common examples from science fiction, such as the Starship Enterprise. The decks of the Enterprise are oriented parallel to the direction of acceleration, which means that people standing on the decks are perpendicular and the force of acceleration would “push” them horizontal to the deck. The same is true of ships of all sizes in Star Wars, Battlestar Galactica, and many other popular science fiction shows.

I know there are exceptions. The ship in Kubrick’s 2001, A Space Odyssey had an interesting design, using a rotating doughnut to generate artificial gravity. This ship was designed, however, for relatively short interplanetary travel¬† and for coasting (rather than accelerating) most of the time. There are sure to be other exceptions – but my point is, they are exceptions, not what we commonly see in science fiction.

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Mar 14 2011

Cognitive Biases and Handedness

One of the mantras of the scientific skeptic is that we need formal logic and scientific methods in order to overcome our cognitive biases. Without a structure to observation and thinking, our biases would overwhelm our conclusions.

This is true not just in the scholarly study of the universe, but in our everyday lives. The more we are aware of the common cognitive biases, the less of a stranglehold they will have on our beliefs. Just realizing the degree to which our perceptions and judgments can be radically altered by seemingly irrelevant factors is very important. In my experience this is often the one critical difference that separates those with a generally skeptical outlook from those more inclined toward uncritical belief. Believers find the subjective reports of others, and their own experiences, to be highly compelling, while skeptics are comfortable dismissing even dramatic anecdotes on the basis of understanding the power of self-deception and cognitive flaws and biases.

In short – believers generally operate under the paradigm of seeing is believing, while skeptics operate under the paradigm that often believing is seeing.

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Nov 09 2021

Brain Stimulation for Cognitive Control

Published by under Neuroscience

A newly published study presents a proof-of-concept for using deep brain stimulation controlled with artificial intelligence (AI) in a closed-loop system to enhance cognitive control, suggesting it might be effective for a number of mental illnesses. That’s a lot to unpack, so let’s go back to the beginning. The most fundamental necessary to understand what is going on here is that your brain is a machine. It’s a really complicated machine, but it’s a machine none-the-less, and we can alter the function of that machine by altering its physical state.

This may seem obvious, but actually people are generally psychologically biased against this view. This may, in fact, be a consequence of brain function itself, which evolved to create a seamless stream of consciousness, an illusion of self unaware of all the subconscious processes that make up brain function. This is why we tend to interpret people’s behavior in terms of personality and conscious choice, when in fact much of our behavior is a consequence of subconscious processes. We are also biased to believe that people can think or will-power their way out of mental illness.

The more we understand about how the brain functions, however, the more it becomes apparent that the brain is just a glitchy machine, and lots can go wrong. Even when functioning within healthy parameters, there are many trade-offs in brain function, with strengths often coming at the price of weaknesses. We need to look out for our own interests, for example, but this comes at the price of anxiety and paranoia. But there are some brain functions that are so basic they are almost universally useful, and impairment of them can cause of host of problems. One such basic brain function is called cognitive control, which is essentially the ability to determine what thoughts and actions will be the focus of your brain’s attention.

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Oct 12 2021

Making Proteins with Plant Molecular Farming

Published by under General Science

As the world is contemplating ways to make its food production systems more efficient, productive, sustainable, and environmentally friendly, biotechnology is probably our best tool. I won’t argue it’s our only tool – there are many aspects of agriculture and they should all be leveraged to achieve our goals. I simply don’t think that we should take any tools off the table because of misguided philosophy, or worse, marketing narratives. The most pernicious such philosophy is the appeal to nature fallacy, where some arbitrary and vague sense of what is “natural” is used to argue (without or even against the evidence) that some options are better than others. We don’t really have this luxury anymore. We need to follow the science.

Essentially we should not fear genetic technology. Genetically modified and gene edited crops have proven to be entirely safe and can offer significant advantages in our quest for better agriculture. The technology has also proven useful in medicine and industry through the use of genetically modified microorganisms, like bacteria and yeast, for industrial scale production of certain proteins. Insulin is a great example, and is essential to modern treatment of diabetes. The cheese industry is mostly dependent on enzymes created with GMO organisms.

This, by the way, is often the “dirty little secret” of many legislative GMO initiatives. They usually include carve out exceptions for critical GMO applications. In Hawaii, perhaps the most anti-GMO state, their regulations exclude GMO papayas, because they saved the papaya industry from blight, and Hawaii apparently is not so dedicated to their anti-GMO bias that they would be willing to kill off a vital industry. Vermont passed the most aggressive GMO labeling law in the States, but made an exception for the cheese industry. These exceptions are good, but they show the hypocrisy in the anti-GMO crowd – “GMO’s are bad (except when we can’t live without them)”.

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Oct 11 2021

Neurofeedback Headbands for Stress Reduction

Published by under Neuroscience

A recent BBC article discusses the emergence of products designed for neurofeedback to aid in stress reduction. The headline asks, “Smart headbands claim to make people calmer. Do they work?” However, the article does not really answer the question, or even get to the heart of the issue. It mostly provide anecdotes and opinions without putting the technology into a clear context. The article focuses mainly on the use of such devices to allegedly improve sports performance.

There are a few premises on which the claims made for such devices are based, varying from well established to questionable. One premise is that we can measure “stress” in the brain using an electroencephalograph (EEG) to measure the electrical activity in the brain. This claim is mostly true, but there is some important background necessary to understand what this means. First, we need to define “stress”. Functionally when researchers are talking about mental stress they mean one of two things, either the stress that results from an immediate physical threat, or the mental stress that results from engaging in a challenging mental task (like doing math in your head while being distracted). For practical purposes the research on EEGs and mental stress use the challenging mental task model.

It his, however, a good representation of stress generally? It is a convenient research paradigm, but how generalizable it is to mental stress is questionable. It can result in objective measures of physiological stress, such as secretion of stress hormones, which is partly why it’s convenient for research and not unreasonable, but it is only a representation of mental stress and might not translate to all “stressful” situations (like sports).

Can EEGs measure this type of mental stress? Yes – a relaxed mind with eyes closed produces a lot of regular alpha waves. A more active mind (and one with eyes open) produces more theta waves and chaotic brainwave activity. EEGs can therefore tell the difference between relaxed and active. How about not just active but stressed? That is trickier, but there are studies which appear to show some statistical differences in the wave patterns regionally with mental stress. So the premise that EEGs can measure certain kinds of mental stress is reasonable, but not as simple as often implied. This also does not necessarily mean that commercial devices claiming to measure EEG markers of stress work.

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Sep 21 2021

Virtual Phobia Treatment

Are you afraid of spiders? I mean, really afraid, to the point that you will alter your plans and your behavior in order to specifically reduce the chance of encountering one of these multi-legged creatures? Intense fears, or phobias, are fairly common, affecting from 3-15% of the population. The technical definition (from the DSM-V) of phobia contains a number of criteria, but basically it is a persistent fear or anxiety provoked by a specific object or situation that is persistent, unreasonable and debilitating. In order to be considered a disorder:

“The fear, anxiety, or avoidance causes clinically significant distress or impairment in social, occupational, or other important areas of functioning.”

The most effective treatment for phobias is exposure therapy, which gradually exposes the person suffering from a phobia to the thing or situation which provokes fear and anxiety. This allows them to slowly build up a tolerance to the exposure (desensitization), to learn that their fears are unwarranted and to reduce their anxiety. Exposure therapy works, and reviews of the research show that it is effective and superior to other treatments, such as cognitive therapy alone.

But there can be practical limitations to exposure therapy. One of which is the inability to find an initial exposure scenario that the person suffering from a phobia will accept. For example, you may be so phobic of spiders that any exposure is unacceptable, and so there is no way to begin the process of exposure therapy. For these reasons there has been a great deal of interest in using virtual/augment reality for exposure therapy for phobia. A 2019 systematic review including nine studies found that VR exposure therapy was as effective as “in vivo” exposure therapy for agoraphobia (fearing situations like crowds that trigger panic) and specific phobias, but not quite as effective for social phobia.

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Sep 03 2021

Trust in Science May Lead to Pseudoscience

Published by under Skepticism

The ultimate goal of scientific skepticism is to skillfully use a process that has the maximal probability of accepting claims that are actually true and rejecting those that are false, while suspending judgment when an answer is not available. This is an open-ended process and is never complete, although some conclusions are so solid that questioning them further requires an extremely high bar of evidence. There are many components to scientific skepticism, broadly contained within scientific literacy, critical thinking skills, and media savvy. Traditional science communication focuses on scientific literacy (the so-called knowledge deficit model), but in the last few decades there has been copious research showing that this approach is not only not sufficient when dealing with many false beliefs, it may even be counterproductive.

A new study offer more evidence to support this view, highlighting the need to combine scientific literacy with critical thinking in order to combat misinformation and false claims. The study focuses on the effect of trust in science as an independent variable, and combined with the ability to critically evaluate scientific evidence. In a series of four experiments they looked at acceptance of false claims regarding either a fictional virus, or false claims about GMOs and tumors:

Depending on experimental condition, however, the claims contained references to either (a) scientific concepts and scientists who claimed to have conducted research on the virus or GMOs (scientific content), or (b) lay descriptions of the same issues from activist sources (no scientific content).

They wanted to see the effect of citing scientists and research on the acceptance of the false claims. As predicted, referring to science or scientists increased acceptance. They found that subjects who scored higher in terms of trust in science were more likely to believe false claims when scientists were cited – so trust in science made them more vulnerable to pseudoscience. For those with low trust in science, the presence or absence of scientific content had no effect on their belief in the false claims. These results replicated in the first three studies, using the fictional virus and the GMO claims.

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