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.