Thinking about reasoning: How to reason more objectively

Matthew McCrudden - 1 May 2015

Why do individuals who read the same information react differently? To some extent, beliefs affect individuals’ reactions. While this is normal, it can be problematic if beliefs interfere with objective reasoning.

In a famous experiment at Stanford in 1979, researchers identified individuals who strongly supported or opposed capital punishment and asked them to read two fictional research studies: the first study reported evidence that capital punishment was a deterrent to homicide and the second study reported evidence that capital punishment was not a deterrent. After participants read each study, they evaluated the convincingness of the study and judged how well or poorly the study had been conducted. Participants rated the study that was in line with their prior beliefs as more convincing and better-conducted.

What makes this finding interesting is the fact that the researchers controlled for the possibility that differences in ratings could be due to the way in which the data in the fictional studies were obtained. For half of the participants, the fictional pro-deterrence study compared the murder rates in several states before and after the adoption of capital punishment, whereas the anti-deterrence study compared murder rates in adjacent states that did and did not have capital punishment. The other half of the participants read the opposite: the pro-deterrence study used an adjacent-states design, whereas the anti-deterrence study used a before-after design. Thus, participants evaluated information that supported their beliefs more favorably than information that challenged their beliefs even though the fictional data were essentially the same! This example illustrates a type of bias known as myside bias. Myside bias occurs when individuals fail to reason independently from their beliefs, such that they evaluate evidence in a way that favors their beliefs and attitudes.

When people encounter information that confirms their beliefs, they often generate thoughts that support the information. However, when people encounter information that challenges their beliefs, they tend to generate thoughts that refute the information. This is normal, and in many cases justified. For example, if someone told you that he had invented a time machine, you would have good reason to question and doubt his claim.

Nonetheless, results from the study described above (and other similar studies) indicate that the participants’ evaluations were not sufficiently justified. Why? When given equivalent pieces of evidence that were open to the same criticisms, they applied different standards of evaluation based on whether it was consistent with their beliefs, not on the quality of the evidence. Thus, a clear indicator of biased reasoning is that a person uses different standards to evaluate belief-consistent and belief-inconsistent evidence.

Reasoning more objectively

How can you reason more objectively? Obviously, there is no simple answer to this question. However, there are at least two ways you can increase your ability to reason more objectively:

(1) be aware of how you reason (2) develop your understanding of the nature of knowledge.

Admittedly, these sound a bit abstract and vague, so I’ll elaborate with some concrete examples.

Become aware of how you reason

The first way you can increase your ability to reason more objectively is to become aware of how you reason. Let’s use an example to illustrate.

John sees a debate between Sherry and Liz about whether global climate change is occurring. Further, let’s assume that John believes that climate change is happening. To resolve the debate, Sherry and Liz both gather information about air temperature. Sherry looks up the average temperature in Tokyo in 2012 and 2013. Then she compares the average yearly temperatures in 2012 and 2013 to determine if temperatures have changed. The results indicate that the average yearly temperature increased significantly from 2012 to 2013. She concludes that climate change is occurring in Tokyo.

Liz looks up the average yearly temperature in Copenhagen over the past two years. Then she compares the average yearly temperature between the two years to determine if temperatures have changed. The results indicate that the average yearly temperature did not increase significantly over the past two years. Thus, she concludes that climate change is not occurring in Copenhagen.

For the sake of simplicity, let’s say that there are two basic types of reasoning that John can use to evaluate Sherry and Liz’s arguments: less-objective and more-objective. And keep in mind that Sherry’s argument (climate change is happening) is consistent with John’s beliefs, whereas Liz’s argument (climate change is not happening) is inconsistent with his beliefs.

Let’s begin with less-objective reasoning. For the belief-consistent argument, John sees from Sherry’s argument that the temperature in Tokyo increased over the two-year time span. Because this is consistent with his views that global warming is a reality, he accepts this information and views it favorably.

For the belief-inconsistent argument, John finds reasons to discredit Liz’s evidence: he argues that two years is an insufficient amount of time in which to measure a change in climate, that to measure a change in global climate it is necessary to obtain data from multiple locations, and that Copenhagen may show less variability in temperature because it is near a harbor. He wonders if Liz’s source is credible.

What makes this less-objective reasoning? Sherry and Liz’s arguments are structurally equivalent and open to the same criticisms. But John notes more problems with Liz’s argument, which is inconsistent with his beliefs. This clearly shows a bias in his reasoning because he is applying a different standard of evaluation to Liz’s argument despite the fact that both arguments are practically identical. The first argument confirms his views and he accepts it at facevalue, whereas the second argument challenges his views and he scrutinizes it to a much greater extent. Thus, he evaluated the belief-consistent argument more favorably than the belief-inconsistent argument, but he bases his judgment on his beliefs rather than the quality of the evidence.

Now let’s look at more-objective reasoning. John reads both arguments and says that they are both weak. Although he believes that climate change is happening and acknowledges that the first argument is compatible with his views, he still points out that evidence of global climate change needs to be obtained from numerous locations around the globe and over a much longer time span than two years. He provides the same rationale for the second argument, which is inconsistent with his views. What makes this more-objective reasoning? As indicated above, Sherry and Liz’s arguments are structurally equivalent and open to the same criticisms.

In the case of more-objective reasoning, John decouples his beliefs from reasoning. That is, although he holds a view on the topic, he does not let his view influence his ability to focus on the quality of the evidence or arguments. He applies the same standard of evaluation to both arguments independent of his beliefs.

As you read this example, you may have wondered whether I presented you a caricature for illustrative purposes and that no one would really reason in this manner. Quite the contrary; in some of my research we’ve had participants evaluate arguments like the ones you read above and they have shown this same type of reasoning. In one study, we had participants rate the strength of arguments that were consistent and inconsistent with their beliefs and had them justify their ratings. The arguments were structurally equivalent and open to the same criticisms. Collectively, participants rated belief-consistent arguments more favorably than belief-inconsistent arguments.

We decided to have closer look at individual participants’ ratings and found that some participants gave identical ratings to both kinds of arguments, whereas other participants rated belief-consistent arguments much more favorably. Then we interviewed them. We gave them the arguments, their ratings, and their hand-written justifications for their ratings. We asked them to explain their ratings and then asked them why they rated the arguments differently (or similarly depending on their specific ratings). Sure enough, their responses mirrored the justifications provided above to illustrate more- and less-objective reasoning.

There are two important ideas to note about the example. First, a defining feature of more-objective reasoning is the ability to reason independently from one’s beliefs. This example illustrates the concept of more-objective reasoning and juxtaposes it with the concept of less-objective reasoning. Second, holding a belief or view does not necessarily lead to biased reasoning. Rather, biased reasoning occurs when individuals do not decouple their beliefs from the evaluation of evidence and arguments. Develop your understanding of the nature of knowledge The second way you can increase your ability to reason more objectively is to develop your understanding of the nature of knowledge. One definition of knowledge is true justified belief. Let’s unpack this.

How can we know for sure if something is true? Well, the reality is we can’t know anything with absolute certainty. But does that mean that knowledge is always a matter of opinion? Of course not. It means that some beliefs are more certain than others and that we have sufficient reason to believe and act upon them, keeping in mind that they may need to be modified in the future. For example, while driving to work, suppose you are at an intersection waiting for the traffic light to turn green, which it eventually does. After a brief delay, you can assume with a high degree of certainty that you can drive forwards without fear of colliding with cross traffic. What would it be like to drive in a city if you were unable to make this assumption? Clearly, we can’t know with absolute certainty that cross traffic will stop at a red traffic light; in fact we have evidence that tells us that cars do collide at intersections. Nonetheless, the probability of driving through an intersection unimpeded by cross traffic is dramatically higher than the probability of colliding with cross traffic.

Now assume that there is a power outage and that the traffic lights stop working. You may become less certain about the likelihood of driving through an intersection unimpeded and approach the intersection more slowly. The situation changed and you had to modify your beliefs and assumptions given the new information.

To develop your understanding of the nature of knowledge, it is important to know what makes some knowledge claims more defensible than others. To do this, you need to understand that, despite the fact that we cannot know something with absolute certainty, some claims are more justifiable than others. For instance, suppose two researchers observe a child solve a complicated mathematics problem. The first researcher claims that the child struggled to solve the problem. To support this claim, the researcher says she struggled to solve the problem, so the child must have struggled too.

The second researcher also claims that the child struggled to solve the problem. To support this claim, the researcher indicates that the child asked several questions while working on the problem, indicated in a conversation that he was frustrated, he looked confused at times, and was unable to solve similar problems on a class quiz. Which researcher provides more convincing evidence? They both make the same claim, but the second researcher provides a greater amount of evidence and the evidence is more objective. This example illustrates that evidence is one source of knowledge and that the quality of evidence affects the certainty of a knowledge claim. That is, higher quality evidence increases the certainty of a knowledge claim.

However, evidence is not the only source of knowledge. To illustrate, suppose I give you two tasks. For the first task, I show you a red marble and a blue marble. Next, you close your eyes and I place the marbles into separate opaque cans. Then, you look into one of the cans and I ask you to identify the color of the marble in the other can that you did not look into. I also ask you how certain you are that you have correctly identified the color. If the marble in the can that you look into is red, then you can be quite certain that the color of the marble in the other can is blue. The second task is similar to the first task, but has one major difference: this time you don’t look into either of the cans. Rather, I just point to one of the cans, ask you to tell me the color of the marble in the can, and how certain you are that you have correctly identified its color. In this task, you have to guess the color in the can and will be much less certain about accurately identifying the color of the marble.

For neither task can you be absolutely certain that you have correctly identified the color. Nonetheless, you will be more certain that that you correctly identified the marble’s color in the first task. The example illustrates that inference can be a source of knowledge in the absence of direct perceptual experience. That is, for the first task, you had to infer the color of the marble by process of elimination. To begin there was a red marble and a blue marble. You saw that the marble in one can was red, and without actually seeing inside the other can, you could infer that it was blue. In the second task, you simply had to guess.

A hallmark of rational thought is the ability to reason independently from one’s beliefs. Thus, it is important to be aware of your beliefs and the fact that they can affect your reasoning ability. On a related note, it is important to understand that although we cannot know anything with absolute certainty, some ideas are more certain than others. So the next time you are at a busy intersection, ask yourself how certain you are that you’ll pass through the intersection safely, and enjoy the ride!