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Cognitive Biases and Handedness

by Steven Novella, Mar 14 2011

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.

There are numerous examples of how malleable our beliefs and perceptions are – to even absurdly arbitrary factors. A recent study concerns the bias of being left or right-handed. Our handedness affects our judgments regarding the quality and “goodness” of things in our environment. There is a clear language bias favoring the dominant right-handers: “right” is correct, while left-handed complements are undesirable, for example. It turns out this is not mere cultural bias, but reflects an underlying cognitive bias. For example:

In experiments by psychologist Daniel Casasanto, when people were asked which of two products to buy, which of two job applicants to hire, or which of two alien creatures looks more intelligent, right-handers tended to choose the product, person, or creature they saw on their right, but most left-handers chose the one on their left.

So, when put into a situation where we have to make a judgment based mostly on our gut feelings or intuition, biases will tend to come out. (It is probably difficult for most people to come up with an evidence-based system for assessing which alien looks more intelligent.) It is possible the common evolved sensibilities will dominate in such situations – most people, for example, might pick the alien with the larger eyes. But that is not what the researchers found – simple handedness was the determining factor.

This is a subconscious bias. If a subject were asked why they chose the alien on the right, they would probably not say, “because I am right-handed and have an inherent bias toward things in the right side of my visual field.” Rather, they would justify their judgment post-hoc – pointing out features that had nothing to do with their actual decision-making, but giving the illusion of a rational choice.

Casasanto found, in the new study, that these biases are also easily manipulated. First he studies stroke patients who were paralyzed on one side of the body or the other. If a right-hander were weak on the left side (as a control) this had no effect on their choice. But if their right side were weak, then their preference shifted to their intact left side. This, however, can be due to damage to the brain, rather than the fact that they are now obligate left-handers. So he did a follow up experiment in which subjects were made to perform a task with a ski-glove on one hand. If right-handers wore the glove on their left hand, again this had no effect on their choices. But if they wore it on their right hand while performing tasks for as little as 12 minutes, then their cognitive bias shifted to that of a left-hander.

Casasanto observes:

‘People generally think their judgments are rational, and their concepts are stable. But if wearing a glove for a few minutes can reverse people’s usual judgments about what’s good and bad, perhaps the mind is more malleable than we thought.’

Exactly. That is why an important step on the journey toward critical thinking is the realization that we are not the objective rational beings we think we are. That is a mere illusion – a lie we tell ourselves to relieve cognitive dissonance. In reality we are horribly biased and easily manipulated. But we can compensate for our flaws – by understanding that we are biased and what those biases are, and by applying critical thinking, logic, and evidence to our conclusions.

17 Responses to “Cognitive Biases and Handedness”

  1. tmac57 says:

    This study has ‘sinister’ implications !

  2. Roberta says:

    It’s well-known in journalism and publishing (in the paper-based world, that is) that items on the right-hand page get more attention than the left, so page 3 of the paper is a better position that page 2. That’s why newspapers will often run the continued stories, masthead, etc on page 2.

  3. Robo Sapien says:

    So, is bias affected the same for those of us who use our third arm?

  4. WDWallis says:

    The journalism/publishing comment is correct but not a direct consequence of handedness. It is a consequence of the fact that newspapers, books, etc are bound on the left-hand side, so when you turn the page you see the right-hand page first, while the left-hand page is still partially obscured. I would guess this relates to the fact that we write from left to right (in a majority of languages), although the reasoning is not clear. And the writing thing is because of handedness, but is logical, not biased (as any left-hander who has smudged their writing will understand).

  5. Max says:

    That’s absolutely right.

  6. Max says:

    Steve,
    “That is why an important step on the journey toward critical thinking is the realization that we are not the objective rational beings we think we are. That is a mere illusion – a lie we tell ourselves to relieve cognitive dissonance.”

    I thought the illusion that we’re rational is what creates cognitive dissonance when we act irrationally, and we relieve it with post hoc rationalizations.

  7. Mario says:

    There have always been a huge mixed up when it come to hand preference, contrary to popular belief (an error that is not committed in the article), there is no hemisphere dominance behind right or left dexterity (up to 80% of lefties show dominance for that task in the left hemisphere just as the righties) this is a term that most of the times is miss used, the dominance is just relative to any given task, there are some that have dominants areas in the left hemisphere there are others that does in the right one.

    What impress me more is how cognitive activity can be correlated with hand dexterity, obviously there is some sort of connection, although causality can not be affirmed right now, but nevertheless our decision making machinery could be more simple that we think, and thats why is to easy to be fooled.

    Dr. V.S. Ramachandran has some very interesting articles about this topic, specially the relation between beliefs and how each brain hemisphere process info.

  8. Bob Carroll says:

    How many subjects were in the study? Were any ambidextrous people tested? How do people in countries where the writing goes from right to left fare? Similarly? As I understand it, neither critical thinking nor logic discovered this bias, if it is a bias. The discovery was made empirically, by testing a hypothesis. Logic and critical thinking are part of the basis for the empirical test, of course, but alone neither of them will discover any biases. In any case, without knowing how many were tested and whether the test has been replicated, I’d hold off the judgment that these scientists have discovered one more way in which we are irrational.

  9. Wes Stillwagon says:

    Just some thoughts:

    The blog begins with, “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.”

    My response: The consideration that the supposedly scientific skeptic actually employs a “holy” or “sacrosanct” axiom as the word “Mantra” suggests, flies in the face of their normal position that nothing is holy and everything is open to challenge, including the mantra. I believe that a skeptic who approaches a philosophical problem and is influenced by a “mantra” or “sacrosanct” axiom should be viewed with skepticism.

    The blog continues, “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.”

    My response: Perhaps no community is less qualified to study, conclude, and profess anything about “common cognitive” processes and their subsequent influence on “biases” than contemporary American scientists and skeptics. While arrogantly believing they know all they need, in reality, they know next to nothing about the structure and dynamics of the individual human psyche and therefore are not suitably qualified to table a substantive opinion. Perhaps even less qualified than the typical American scientist and skeptic on the matter of the human psyche within which “cognitive biases” are the source, are American philosophers. After all, such a consideration of “cognitive biases” IS a philosophical one and not a scientific one since the term “cognitive” is not scientifically defined by the skeptic blogger, right? Yet, can science lead the world ahead without philosophy? I don’t think it can do as well without philosophy as this is the key to taking cold facts, function, and structure and adding the aesthetics, right? Sometimes aesthetically pleasing form supports and improves function. Also such discussions should consider the fact that the skeptic is using his or her psyche (the tool) to study the psyche (the object or subject). No other science has that restriction to pure objectivity.

    Next he said: “Just realizing the degree to which our perceptions and judgments can be radically altered by seemingly irrelevant factors is very important.”

    I say, Seemingly irrelevant factors may be a strong influence however determining the rate, extent, or value of their relevance may require the judger to rely upon some irrelevant, irrational, or subjective influence, right? As the blogger states, it may be important but the conclusion of how much is very theoretical, isn’t it. It is impossible to prove scientifically especially since the skeptic has no real scientific understanding of the individual human psyche.

    He said, “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.”

    I say, The blogger’s pigeon holing is simply too simplistic, convenient, and given the breadth of individual psychological styles, an impossible to scientifically support conclusion. A skeptic holding this opinion should not consider themselves sufficiently qualified to conclude such a thing.

    Back to the box with two pigeon holes, he states: “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.”

    This is a bit beyond my ability to paraphrase or understand.

    I say that skeptics, by virtue of their negative expectations that something unproven is automatically proven false rather than concluding that perhaps they need more information for their judgment, closes the windows of their mind — not a very scientific or psychologically useful attitude.

    I find it wearying to continue in the face of the blogger’s unscientifically drawn conclusions based upon an elementary understanding of the individual human psyche.

    Wes Stillwagon.

    • tmac57 says:

      This seems like a collection of straw man arguments to me,but if someone were to entertain your points,then who would YOU consider a valid source of knowledge about human cognition and biases, if not scientists,skeptics and philosophers?

  10. Wes – your comment is a mass of logical fallacies and smug nonsense.

    First, the term “mantra” is often used colloquially simply to mean something that is said over and over – not implying (as the context of my blog post should have made obvious) holy or sacrosanct. So your first point is a straw man based upon your deliberate misinterpretation of a single word. This is a common debate ploy, not not very intellectually honest or rigorous.

    You next proceed to an ad hominem attack against “American scientists and skeptics.” One can only conclude from that statement that you are a bigot.

    You then give us another straw man, with the tired “mantra” of the crank that skeptics “arrogantly believing they know all they need.” Please justify that statement with some supporting evidence. It is the skeptics who profess doubt, the limits of human knowledge, and that, in fact, we need to be humble about our current knowledge. In fact, that’s what this very blog post is about. That statement alone makes it obvious to anyone actually familiar with skepticism that you don’t know what you are talking about.

    You seem to miss the point that in this article I am referring to the kind of research that is empirically demonstrating the principles I am discussing – that we are influenced by subconscious biases – so yes, it can be studied scientifically. The point of scientific methodology is to control for such biases (again, a point of the post you seem to miss.)

    Regarding my “pigeon holing” – read the sentence again. I was careful not to create a false dichotomy, or to be too simplistic. But you are committing the fallacy of the false continuum – using complexity to deny that there is a pattern that can be meaningfully discussed. Like it or not – some people have a habit of thought that is more inclined to critical analysis and doubt than others. And yes – this can be quantified and studied scientifically – there are plenty of studies that compare the psychological traits of those who score differently on surveys of belief (your apparent ignorance of the psychological literature notwithstanding).

    You conclude with yet another straw man, “I say that skeptics, by virtue of their negative expectations that something unproven is automatically proven false.”

    Skeptics do not conflate unproven with proven false. In fact we take great pains to point out the difference. Your impression of skeptics is clearly biased, and not based on anyone I know.

    But thanks for playing “name that logical fallacy” – it’s been fun.

  11. Seth says:

    I wonder which biases are generated from Manos: The Hands of Fate.

  12. As the article was drawing to a close and I saw the sentence:

    “But we can compensate for our flaws – by…”

    I imagined that the sentence was going to end:

    “…wearing a ski glove on our subordinate hand for 10 to 12 minutes, 3 times per day.”