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.
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.
37 Responses to “Cognitive Biases and Handedness”
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Great post, very, very enlightening, Religious fanatics need to read this wonderful post. They simply believe what was written in their so called holy book yet they have the audacity to say that Psychics and New Agers are wrong and evil. Most Religious and Atheistic people are quit uncritical when it comes to their own belief systems. Look at how easy it is to manipulate us, I like how Casasanto manipulated peoples judgements.
We have all been manipulated too, Natural Selection has manipulated our brains into believing that we are merely a biological body, in the long painful process of evolution our ancestors lost many abilities such as Telepathy, Precognition and the ability to peer into the Spirit World, these traits were not necessary for the Physical Machine to reproduce and spread it’s genes. However we must break free of the manipulation that natural selection has done to our brains, in the same way Physicists rewire their brains to study Quantum Mechanics, we too can rewire our brains and realize that we are eternal spiritual beings having a temporary human experience.
Love and Peace 🙂
Interesting bit on the left versus right handed-ness in decision making. Could this be used or has been used in marketing and advertisement? I wonder if it also applies to presenting data in graphic form. I also wonder if reading left to right or right to left has any impact on this too. any thoughts Dr. S?
“Physicists rewire their brains to study Quantum Mechanics”
Oh, do tell me more. I studied Quantum Mechanics in college but I’m an engineer. I must have missed out on the lesson on brain rewiring since I wasn’t training to by a physicist. (shovels fresh meat to the troll)
Hate and War >:{
@ Draal, it is difficult to explain anything to someone as ignorant as you
you give up so easily.
Hi Stephen Novella –
Interesting article. Thank you.
I’d be interested in your thoughts on the apparent association between left handedness and autoimmune disorders.
– pD
Unfortunately when people first hear that their beliefs and judgments are not the pillars they thought they were, they often conclude that no one can ever know anything at all. Then they go on believing what they did before and just figure it’s on faith and people who believe otherwise are just choosing to on faith as well.
Does this mean that an ambidextrous person is inherently just a teensy bit more fair than everyone else? And is the effect big enough that it’d be worth factoring into decisions about how to lay out a courtroom, for example, or which side of the road we should drive on?
@Chris Sham:
“Does this mean that an ambidextrous person is inherently just a teensy bit more fair than everyone else?”
Great question. +1
I wonder if is really dominant hand that matters, or dominant eye?
The coupling between the left and right sides of the brain is limited (but not small). It is not unreasonable that there would be different biases depending on which side was doing the primary data processing. I presume that some of the effect comes from perceiving things from a right handed vs a left handed perspective. Presumably the processing in the left side of the brain is somewhat different than in the right side of the brain and being able (willing?) to draw on the perspective of both sides of the brain may be important in reducing bias.
The “wisdom” of crowds only occurs when the individuals in the crowd think and behave independently. When they are not independent, then you don’t have a crowd, you have a mob. The Delphi Method of making predictions depends on the different experts being independent. It is the independence of the decisions by individual actors that removes “bias” by virtue of the different biases “averaging out”. This is only true to the extent that the biases are different and do “average out”. Any kind of a difference is going to lead to a difference in bias and will tend to produce a less biased result (than the most biased of the group). When the group adopts the bias of the leader you have what is called groupthink. Good leaders actively work to avoid groupthink. That is what Dr Novella is talking about in how knowing your biases can help you to avoid them.
There is a technique called EMDR, which is not very well established and might not actually be valid. What it consists of is compelling attention to switch from a left-eye dominant to a right-eye dominant perspective while thinking of a disturbing memory. When it was tried on me it didn’t work, but my conceptualization of how it might work (if it actually did work) was that by switching perspective from a left-side to a right-side and back, that the only memories that could persist would be those that could “map” into both sides. What ever couldn’t “map” onto both sides would be lost or at least attenuated.
A reason this is especially interesting for me is that from childhood I have had the ability to spontaneously switch my perspective from a right-eye dominant to a left-eye dominant and back at will with sub-second timing. I wonder if that is a partial explanation for my complete lack of intellectual bias. 😉
There is another thing which might be related, the ability of “mirror writing”.
http://en.wikipedia.org/wiki/Mirror_writing
I remember reading some articles about it where people who could do mirror writing found that their writing abilities were different when writing in mirror script than in direct script, and enough different that one person wrote their thesis in mirror script and then copied it on transparencies to convert it to direct script to edit it for final form.
You “feel” you have more ability to control what appears on your dominant side, than what may have snuck up on you unawares on the less dominant side. Otherwise you ask yourself subconsciously why things have “chosen” that side to appear on. In short you trust the expected more than the unexpected.
Which is how bias equates with ignorance. We trust what we think we know rather than distrust the extent to which we think we know it.
SkeptialAtheist,
“Belief” has very little to do with science. What will your beliefs or my beliefs matter to anyone once we are dead and gone?
Statements about the world we share that survive tests to prove them false, that can be independently corroborated, and that do not violate logic, are more likely to be true than otherwise.
Most everything else is personal opinion. Nothing wrong with opinions, unless you’re prescribing them rather than simply sharing them.
@titmouse: your response is a typical Atheistic response, we spiritualists have learn to accept reality as it is.
We can’t escape from the uneasy fact that the death of our bodies doesn’t mean that we no longer face the consequences our actions.
We are living in a deeply interconnected universe, we are part of everyone and everything.
Life/Love is eternal, Death is just a horizon.
Love and Peace 🙂
I think our post decision explanations are the most interesting point in this. We assign a arbitrary reason to our right handed choice and truly think that this is why we made the choice.
Our minds rebel against the irrationality of the “right handed” choice and yet making up an arbitrary reason is even more irrational.
What purpose does making up a post choice explanation serve? Why not be fully cognizant of our bias? What causes our brains to handle it this way? Is there an evolutionary advantage to our brains working like that?
“Is there an evolutionary advantage to our brains working like that?”
Yes. Short term survival advantage.
This study is quite interesting in that it does show one reason self-report can be unreliable as a research tool — people often don’t really know the reasons for their choices. In a 1997 study by Adrian North and colleagues, either German or French music was played in a store. On the German music days, more German wine was purchased. On the French music days, more French wine was purchased. Only 1 in 44 people spontaneously mentioned, in an interview, that the music influenced the choice. Furthermore, 86% said, when asked directly, that the music did NOT influence their choice.
Skeptical Atheist,
Science means that you can double check what I say, and vice-versa.
What you propose is mere assertion or “the loudest voice with the biggest smile wins.” I hardly thing that’s “love.”
Dr. Novella:
So did the cognitive bias influence the cultural bias? Or was it the other way around?
And a reminder that even words from other languages are biased. Adroit means competent in English, but is derived from the direction “right” in French. Gauche means tacky and awkward in English, but the direction “left” in French. That freaked me out when I was learning tourist French. Then I remembered the T-shirt worn by a left-handed friend:
Left handers are always in their right mind!
I understand exactly what you mean. Often I realize that my decisions are based somewhat on something’s colour, what it reminds me of, what its mental connotations are, etc. I hope you can find other things, like our handedness, that aid us as humans in making gut decisions so they are easier to recognize. I hope this does not lead to massive mental hysteria. (I, and others like myself, think we’re thinking things subconciously that I’m not, due misinformation being spread. Mental Hysteria. ) (Interesting Experiment. I can see this becoming a viscious, endless cycle of confusion. Much like overthinking things.)
This shows how important it is to teach young people to think critically, to think independently, and to work to be self-aware and open-minded at the same time.
Also important to teach them about the results of these sorts of studies (to help with the self-awareness goal)
Did you ever notice that in photos of analog watches for advertising – it’s always 10 after 10? It’s because the hands make a smile.
I’ve saved a lot of money by being aware of the biases that Wall St would like me to operate under 🙂
@Skeptical Atheist
“We can’t escape from the uneasy fact that the death of our bodies doesn’t mean that we no longer face the consequences our actions.
We are living in a deeply interconnected universe, we are part of everyone and everything.
Life/Love is eternal, Death is just a horizon.”
How do you know these assertions are true? What evidence do you have?
And just so you know, most people, like me and, I’m sure, like @titmouse, for example, love “love and peace” every bit as much as you do. Just sayin’….
It seems they assumed the people didn’t know they were biased, but I’m left handed and am purposefully biased. I don’t go out of my way, but I do favor the left, and lefties, and if I pick something on the right, I’m quite aware it’s on the right. Maybe being a lefty has made me more aware of left vs. right, sometimes I point out to a righty how this or that is easier or catered to them, and they are completely oblivious, as it was designed for them to be convenient (which makes it inconvenient for me).
By the way Dr. Novella, you are wonderful and I love your blog, but you have some of the weirdest trolls.
If SA is really like this and not just poe-ing I hope she realises that the longer she hangs around here, the more she will begin to think like us.
That being said, I can’t resist:
–Natural Selection has manipulated our brains into believing that we are merely a biological body, in the long painful process of evolution our ancestors lost many abilities such as Telepathy, Precognition and the ability to peer into the Spirit World–
Psychic Prehistoric Primates!!!
I know I’m setting myself up for a cwfong riposte but…
What happens if you’re a right handed bowler and batsman but you put your left ear to the telephone and your left eye to the microscope.
sara,
“What purpose does making up a post choice explanation serve? Why not be fully cognizant of our bias? What causes our brains to handle it this way? Is there an evolutionary advantage to our brains working like that?”
One of the great lessons of evolution is that not every thing has a survival advantage. Some things just don’t matter either way. Some things are side-effects of some other things that have, or had, a survival advantage. Some things had a survival advantage that has been lost. Some things didn’t matter and then came to matter.
It is an error to assume every characteristic is there because it contributed to survival.
cwfong,
And Jonah lived in a whale. 😉
cwfong,
Your other post sounds interesting, but I can’t quite get the whole gist of it.
…but I know better than to ask you to expand on your comment.
🙁
–“What purpose does making up a post choice explanation serve?”–
It’s quick, makes us feel more in control and of course gets rid of any negative feelings that might affect our belief that we are wonderful human beings without biases. It’s important for our well being.
The alternative would probably be over-analysis of every motive from sketchy knowledge about our random biases. Which is probably as bad an alternative.
eiskrystal, I plan to stay in this great blog for a long time to come, and don’t worry I won’t be influenced by your way of thinking, sure all of you have expanded my world, but there is nothing overwhelmingly new here, other than the fact we can learn a lot about the brain from Dr. Novella.
I am pretty familiar with Atheistic blogs, I have been hanging around the best and the most angry of them all: Keith Augustine, Greta Christina, PZ Meyers, Ebon Musings, JREF and of course Richard Dawkins website.
Can anyone tell me why is Daniel Dennets website so boring, I go there every day hoping for something new and exciting but there is almost nothing there, he should create a blog.
I agree with some of what the other commenters have alluded to, that “handedness” is given an status that it perhaps doesn’t deserve. It may be a bias due to its history and apparent ease of measurement, but at best it is a weak surrogate marker.
There are all sorts of sidedness we could consider including which eye, ear, leg, tilt of the head, sleep position etc that a person prefers for a given task. Even these are task-specific, a person may write with their right hand and bat lefty. I’m not sure why any one of these tasks is considered more important than any other.
“We spiritualists have learn to accept reality as it is.”
You see things as you want to see them, not as they are. This is why you cannot define what you mean by spiritualist, nor provide evidence for the things you say
That is absolutely fascinating — that the bias would shift in only 12 minutes of difficulty using the dominant hand is particularly interesting. It clearly has nothing whatsoever to do with eye dominance but rather with grasping dominance. Clearly, touch and the ability to manipulate things is a great deal more important to how we think than we tend to realize.
Fascinating! I wonder how this would play out in double amputees, people with phantom limbs, people who are completely paralyzed, and, as others pointed out earlier, people who are ambidextrous.
SA, doing the same thing over and over and expecting different results is Einsteins definition of insanity. You need to ask yourself what are your biases that compel you to keep doing the same things over and over and expecting different results.
eiskrystal, sometimes post-hoc explanations are correct. Usually they are. It is when post-hoc explanations are generated to make us feel a certain way that they are usually wrong.
Sometimes the best survival tactic is to generate a wrong post-hoc explanation. This is why abused children become provocative and blame themselves for being abused. It gives them the illusion that the abuse is something they have control over which makes it more bearable.
To avoid being killed, abused people will even adopt doublethink. I think a lot of the adoption of religion is due to this kind of thinking. That is why many of the most “religious” groups have Gods that are abusive and worthy of being feared. That fear compels adherents to obey the priests to avoid the torture they say their God has for them if they don’t. Once they have convinced themselves of the “truth” of their religious views, they forget that they did so out of fear. That forgetting is a good survival feature. It is much easier to give the impression of loyalty if you are actually loyal. Stockholm Syndrome is a good example of a post-hoc emotional reaction which makes no sense other than as a survival tactic.
Cali, could you share your thinking in how it “clearly” has nothing to do with eye dominance?
Everything you write I seem to be able to relate to well. Unlike your most recent article which I see as misdirected sarcasm, a slap on the back to other skeptics and not a tool for change.
Recently I’ve gone through some massive changes in terms of my world view as well as my own eqo as an individual. I’ve read Darwin, Hawking, Sagan, watched some of the more recent Richard Dawkins TV documentaries.
As a consequence, my thirst for more knowledge has risen substantially. I wish to know more in less time. My life now evolves around providing myself with more knowledge and experience. I used to be comfortable working my dayjob, I didn’t really plan on any higher studies. Now I’m looking into so many different fields of study that I hardly have time to just sit down and eat.
It is like the raging monkey deep below my cerebral cortex finally has no say whatsoever. It is happy doing whatever I want, feeling whatever I want. It is a glorious sensation, though I fear it is illusory.
# cwfong “Short term survival advantage.” Define that. I recognize that we need quick decisions for desperate survival moments, but where is the advantage to not recognizing why those decisions were made?
In a fight or flight situation, we should still be hijacked by our lizard brain, and with good reason. That doesn’t mean we shouldn’t know later why the brain did what it did. And in most of our life, transparency would be of value in immediate decision making.
# BillyJoe7 “It is an error to assume every characteristic is there because it contributed to survival.” That is true. The additional amount of brain power it takes to cover up the decision seems like an adaptive thing to me. But that is just intuitive and probably based on cognitive bias. Its certainly not based on any science I’m aware of. 😉
# eiskrystal “The alternative would probably be over-analysis of every motive from sketchy knowledge about our random biases.” I guess. Except that in my premise, you would have actual, not sketchy knowledge of bias, because you would understand your logic in decisions.
I recognize that we can’t stop and think for every decision we make. We would be paralyzed, since arguably every movement we make would require a decision to make that movement. That doesn’t mean that when we choose to examine a decision that we shouldn’t be able to justify its roots. The fact that a computer does an automatic routine, doesn’t mean that its logic cannot be read when necessary.
# daedalus2u “sometimes post-hoc explanations are correct. Usually they are. It is when post-hoc explanations are generated to make us feel a certain way that they are usually wrong.” I don’t think this is true all of the time. As many of these studies show, we randomly assign rationale to every day actions, that have no relationship to making us feel any particular way. (someone mentioned the wine purchases that were correlated to the music, but none of the buyers were aware of it. They randomly assigned other reasons.) Although, I think people do use these kinds of post decision rationales to adapt to unbearable situations.
Sara,
The advantage is to maintain a form of self trust in the effectiveness of our subconscious decision making processes. Early humans didn’t have time to second guess themselves, even though they had no idea where or what their behavioral instincts were evolved from.
They had no time to ask themselves if their urge to throw the spear with their right hand and hold the shield in their left hand was reasonable, and no way to wonder if these could be separate functional strategies controlled in separate parts of their brains.
Perhaps it’s just established pattern dependency. Off-hand, I’m not certain if left- or right-handedness is an exclusively genetic trait or an exclusively learned one. More than likely, I’d imagine, from a genetic standpoint, the body generated from those genetics will be given to exhibit a certain level of competency for tasks on a certain side. As a for instance, the child of two right-handed people will be comprised from a combined genetic profile that tends towards right-handed muscular physiology. I, personally, received my shoulders from my father and, like him, am more comfortable carrying static heavier loads on my left side, yet am more comfortable accomplishing harder, more dynamic tasks (such as leverage, pushing, pulling) with my right side.
Also, to my point, is the learned aspect in the musculature. Over time, emphasis would be placed more and more on this specialization simply because those parts of the body would be more capable in those specialized tasks, building upon the initial state provided from genetic stock. I would expect there is also a mental lean as well; a reliance on certain nervous system activation patterns paralleling past successes. Is a right-handed person that way only because they were born that way or because at some point in their early development did they see people preferring their right-hand and, in perceiving that inclination, mimicked it.
The result is probably an amalgamation of all these aspects.
At adulthood, like those that participated in the example study, is this particular bias a cause or result? What I mean by that is, are we seeing that the “target acquisition” part of our mind is biased due to reliance on its established nervous system firing patterns and trained physical aptitudes (making it the result of experience) or did things start at the very first development stages of the brain (making it the cause from then on, manifesting in adulthood as the bias in the study)?
Please excuse the lengthy comment… It’s more vetting out the concept for myself than anything. I am still posting it in the hope it’s more constructive than hindering to the conversation.
The human tendency in judgement to attach significance or bias where there bears no weight, without their being conscious of it, is disconcerting to say the least. Great post, food for thought. As you might imagine, my mind gorged itself. ^_^