Biases and Conflicts of Interest

The first principle [of critical thinking] is you must not fool yourself—and you are the easiest to fool! —Richard Feynman

[A]ll men are by nature provided of notable multiplying glasses, (that is men their Passions and Selfe-love,) through which, every little payment appeareth a great grievance; but are destitute of those prospective glasses, (namely Morall and Civill Science,) to see a farre off the miserises that hang over them, and cannot without such payments be avoyded. —Hobbes, Leviathan Ch. 19


A bias is an inclination or a prejudice that can interfere with our reasoning. Biases are best understood as the product of psychological elements such as our attitudes, desires, fears, and motivations. They mess up our reasoning because of how our brains work. Fortunately, merely having a bias doesn’t mean you’re going to make a mistake in reasoning. That depends on the kind and strength of the bias.

A legitimate bias is simply having a point of view but not allowing that point of view to distort reasoning. An illegitimate bias is one that interferes with one’s judgment or reasoning and causes the arguer to poorly or dishonestly represent reasons and evidence or make weak logical connections between premises and the conclusion.

There are different strengths of bias: A vested interest is when the arguer stands to gain in some important way if their conclusion is true. I.e., there is a personal benefit to the arguer if their position turns out to be true or is believed to be true.

A conflict of interest is a vested interest on steroids: It usually occurs when personal motives or interests (i.e., secondary interests) risk interfering with or influencing a professional or legal obligation or judgment (i.e., primary interests).  Primary interest refers to the principal goals of the profession or activity, such as the protection of clients, the health of patients, the integrity of research, and the duties of public office. Secondary interest includes not only financial gain but also motives such as the desire for professional advancement and the wish to do favours for family and friends.


Suppose you happen to run a fruit stand for your summer job. At the beginning of the day you had 10 apples but you sold 6 over the course of the day. The sun is setting and you need to do inventory. You are a Millennial and as such are unable to do simple algebra in your head. You look down at the cellphone that hasn’t left your hand all day and pull up the calculator app. You carefully punch in the keys 10-6=7. “What? That’s weird,” you think to yourself. “I’m not sure what the answer is but I know it isn’t 7.” You try again and you get the same result. Fortunately for you, a GenXer is passing by. “Hey, Grampa!” you call. “Could you help me for a moment? What’s 10-6?” 4, replies the old man.

There are two general ways we can think about errors in reasoning. The first involves kinds like what occurred at the fruit stand. You were putting in all the right facts but there was a processing error with the app. We can think of this first kind of error of having to do with how we think. The human brain has some glitches in the programming as a result of our evolutionary history. The other kind of error has to do with what we believe. In the above example such an error would be equivalent to using the wrong numbers for your calculation. That is, inputing the number 11 when there were in fact only 10 apples. Even if you did the subtraction correctly, you’d end up with a false belief about how many apples you have.

The line between these two kinds of errors isn’t clearly defined. Some errors will share properties of both. Nevertheless, distinguishing between the two types of errors is a useful way to think about the kinds of obstacles we encounter to good reasoning. This lesson will focus on the first kind of error: errors to do with how our brains process information; i.e., the built in glitches in our brains.

Mommy, What’s a Bias?
A bias is an “inclination or prejudice for or against” some fact or point of view. In arguments, this means that we are prone to giving undue favour or neglect to some fact or point of view. Everybody does this (except me, of course); it’s part of being a human being. As philosopher Richard Feynman says, “the first principle [of critical thinking] is you must not fool yourself—and you are the easiest to fool!”

There is a wealth of evidence in psychology demonstrating that we begin with a position first then collect or reject evidence and reasons to support that pre-existing position. Our pre-existing position is usually grounded in emotion/preferences rather that any kind of careful deliberation.

The more emotional our investment in an issue, the greater the likelihood that some kind of bias has crept into our supporting arguments—in attributing either undue strength to a supporting assertion or in overlooking or dismissing contrary reasons or evidence. To quote another philosopher, David Hume, “reason is slave to the passions.”

Kinds of Biases

Biases Caused by Individual Interests or Group Identity

Click Here for Comic Explaining Biases

There are many ways to think about biases. One distinction is according to whether the bias is associated with individual interests or group interests. A bias that is associated with individual interests will likely cause the arguer to favor their own point of view. One extremely interesting kind of individual bias is called biased fairness. Biased fairness occurs when people are presented with the exact same situation but are situated in different positions. They think their judgment is objectively fair but their particular position in that situation in fact distorts their reasoning.

E.g. 1
Situation from position A: If someone sues you and you win the case, should they pay your legal costs? 85% of respondents say, yes.

Situation from position B: If you sue someone and lose the case, should you pay their legal costs? Only 44% say, yes.

Notice that it’s people relative position in the situation that influences their intuitions of fairness rather than facts about the situation. Self-interest distorts intuitions of fairness.

E.g. 2
In a real world case, researchers examined historical records of salary negations between teachers’ unions and school boards. School boards typically set salaries relative to comparable school districts. Researchers discovered that the source of disagreement often arose due to what counted as a comparable district. Teachers thought their district was comparable to higher paying districts and the school boards thought it was comparable to lower paying districts. Notice that both agreed that the fair thing to do would be to compare to other districts but their relative position in the situation led them to choose different sources of comparison.

Biased fairness shows how individual self-interest biases judgments of fairness.

Our relation to a group and how that group relates to important components of our identity also distorts our ability to reason well. Group bias causes us to believe a position on a issue, not because of its merits, but because of our affiliation with a group and that group’s position on the issue.

E.g., 1.
In the first part of the experiment Democrat and Republican voters were presented with Democrat and Republican welfare policies. The Democrats preferred the Democrat polices and vice versa. In the second part of the study, the experimenter merely switched the label on who the policy belonged to. In this case Republicans preferred Democrat policies while Democrats preferred Republican policies! Group bias overwhelms our reasoning capacities and most people choose whatever their group chooses without critically evaluating the content.

Today, a glance at history shows the effect of group allegiance on policy support. For example, the carbon tax and Obamacare which Republicans today abhor were originally Republican policy proposals in the 90s. Democrat support for the War on Drugs was solidified when Bill Clinton rallied behind it. Similarly, Clinton’s (at the time) popular Welfare Reform was originally a Republican policy which many Democrats had previously opposed.

Other well-known instances of group bias has to do with the relationship between political ideology and science. Suppose I know that you’re a Liberal. Should knowing your political ideology allow me to predict you beliefs about bio-chemistry or particle physics? It would be really weird if it could since most scientific beliefs and political beliefs don’t seem to be logically connected in any obvious way. And that’s just the point. In fact, based on your political identity I can fairly confidently predict your views on climate change, nuclear energy, evolution, vaccines, and GMOs!



But why? Scientific and political beliefs aren’t logically connected. One is about the best way to order society and allocate resources while the other is about the nature of matter at various magnitudes. Well, perhaps they aren’t logically connected but they certainly are psychologically connected. In order to preserve identity and group membership people overwhelmingly adhere to whatever beliefs their political tribe adopts in respect to science. Their capacity to reason has been overwhelmed by a glitch in their hardware: The tendency to conform one’s view with that of one’s tribe rather than to evaluate the evidence impartially and systematically.


From an evolutionary point of view group bias makes sense. If our core beliefs were different than those of our group, we would not longer be part of the group! As social creatures, maintaining harmonious membership in a group is vital to our well-being. Another reason why group bias makes sense is that it’s efficient. No one has time to do deep research on every issue. I know that people in my group mostly share the same values as me and so it’s not unreasonable to adopt whatever position the group takes. Their position is likely to conform to my values and beliefs.

Notice that both reasons that explain group bias are not reasons to suppose that my beliefs are true rather they only ensure that I’ll be a happy group member. This in part explains why entire groups of people can be so devoted to, what are to outsiders, obviously false beliefs.

Political biases are so strong that they can even overwhelm our ability to do math! Click here for a write up.
And here’s more on how your politics affects your non-political beliefs: Article

Legitimate and Illegitimate Biases

We’ve established people (except me) have biases. Now what? Do we automatically reject everybody’s arguments ‘cuz they’re biased? Nope.

We can make a distinction between legitimate and illegitimate biases. The distinction will depend mostly on how opposing reasons, evidence, and arguments are portrayed, and if there are any intentional important omissions or distortions.

A legitimate bias is simply favoring a point of view but not in a way that misrepresents the opposing position. It still allows an impartial observer to fairly evaluate the proposed point of view.

As you might have guessed, an illegitimate bias is one in which the arguer poorly or dishonestly represents evidence and reasons or makes weak logical connections between premises and the conclusion. Any website or blog with a strong political bias in either direction will usually provide excellent samples of arguments with illegitimate biases. We can distinguish between two kinds of illegitimate biases in terms of their strength:

Vested Interests
A vested interest is when an arguer (or someone paying the arguer) stands to benefit from their point of view being accepted. When vested interests are involved there’s a very high likelihood of illegitimate bias.

For example, certain industries spend millions of dollars to pay lobbyists and “donate” to politicians. It’s not unreasonable to suspect illegitimate biases in those politicians’ arguments on behalf of the industries for special treatment or tax and regulatory exemptions.

Not all vested interests need be financial. One might be motivated by the desire for power, fame, revenge, attention, sex, etc.. or to get out of trouble/prove one’s innocence.

We should be cautious of dismissing arguments out of hand just because the arguer has a vested interest in the outcome. That someone has a vested interest tells us nothing about the argument’s validity and soundness which should be evaluated independently. When we identify a vested interest, it simply means we should be extra cautious about illegitimate biases (and omissions). It doesn’t automatically follow that the argument is invalid or unsound. To figure that out, you have to actually evaluate the argument and evidence.

Similarly, when I have a vested interest in a conclusion, I should be on the lookout for poor reasoning on my own part.

Conflict of Interest
A conflict of interest is a vested interest on steroids; i.e., when vested interests are extreme. It usually occurs when personal motives or interests (i.e., secondary interests) risk interfering with or influencing a professional or legal obligation or judgment (i.e., primary interests).  Primary interest refers to the principal goals of the profession or activity, such as the protection of clients, the health of patients, the integrity of research, and the duties of public office. Secondary interest includes not only financial gain but also motives such as the desire for professional advancement and the wish to do favours for family and friends.

In professional settings, conflicts of interest have to be disclosed. For example, in medical research if a university study of a drug is funded by the company that produces the drug, this is a conflict of interests for the researchers. Their labs and job depend on the funding. Thus, sources of funding must be disclosed at the beginning of any research that is produced. This is actually quite a big problem in medical research because drug studies that are funded by the drug producer systematically have higher positive results than if the same drug is studied by a neutral party. For more info check out the link:Medical research and funding.

Illegitimate bias in medicine (and elsewhere) isn’t only on the industry side. Often people who oppose something for ideological reasons are just as guilty of bias.

An important example of a conflict of interest in medicine that wasn’t disclosed was Andrew Wakefield’s anti-vaccine research article in the Lancet. He did not disclose in his research that he had been paid several millions of dollars to do research on vaccines by a company that was developing an alternative to the conventional vaccine.

There was a clear conflict of interest because he stood to gain so much if his research showed that standard MMR vaccine was unsafe. The company that had funded the research was developing an alternative that they wanted to bring to market. If they could generate fear about the existing vaccine, they’d have the whole market to themselves.

In the end, his results were never replicated, his methods shown to be unethical, his data drawn from a statistically insignificant sample size (12 children), and the article was subsequently retracted by the publisher. However, because of the fear that came about because of his “research,” there was and continues to be tremendous damage to public health. To learn more click here.


We all have biases. What matters for critical thinking is the degree to which they distort the presentation of evidence and reasons in arguments both for and against the arguers position. Biases are illegitimate when they cause distortion such that arguments cannot be fairly evaluated.

For some excellent examples of how biases affect how we interpret the world, this is a beautiful article..



(a). Choose any 3 of the following articles.

(b). Decide whether there is an legitimate or illegitimate bias.

(c). If it is an illegitimate bias decide whether it is a vested interest or a conflict of interest. Be prepared to discuss your answer in recitation.

1. Funding for climate  change denial research:

2. Vaccines, Wakefield, Autism:

3. Perception of food:

4. Cash for Kids:

5. Oil and Gas Tax and Regulation and Campaign donations: see also:

6. Anti-Marijuana Legislation and Alcohol Lobby: also Link

7. Immigration Legislation and Private Prisons:

B. In the news during the election there was much hullaballoo regarding conflicts of interest between Hillary Clinton and the Clinton Foundation. As you should know by now from the course, when events and issues are related to politics biases will overwhelm most people’s ability to gather and process information. In short, their capacity to think critically is compromised.

Here are two different articles covering the issue, one from the right and one from the left. Read them both and answer the following:

a. How do biases affect the contents and arguments in each respective article?

b. Based on both articles, do you think there was an conflict of interest or vested interest, or neither? Be prepared to defend your answer in recitation.

Critical Thinking in The Real World

C. The Emoluments Clause (click link for in depth explanation) of the Constitution states that “No Title of Nobility shall be granted by the United States: And no Person holding any Office of Profit or Trust under them, shall, without the Consent of the Congress, accept of any present, Emolument, Office, or Title, of any kind whatever, from any King, Prince, or foreign State.” The basic idea is that no public official can receive gifts of any kind (financial or otherwise) without prior approval from Congress. A purpose of the clause is to prevent the corrupting influence of foreign power on American government. Critics of Trump allege that his vast international business holdings and dealings create potential conflicts of interests and create potential violations of the Emoluments Clause. That is, he will potentially face situations where he has to choose to prioritize his business interests or those of the American public. Furthermore, they allege that since Trump hasn’t released his tax records it’s impossible to ascertain the extent of his foreign business. Consequentially, it will be impossible to determine whether he receives emoluments in the form of benefits to his business interests.

a. Do you think Trump’s international business holdings (known and unknown) create potential conflicts of interest or potential violations of the Emoluments Clause? Explain your answer.

b. If you answered ‘no’, but that the Clinton Foundation Global Initiative would have created conflicts of interest for Hilary Clinton, explain the relevant difference(s) in the two cases.

c. If you answered ‘yes’ above but that the Clinton Foundation Global Initiative didn’t and would not have created conflicts of interest for Hillary (had she won the election), explain the relevant difference(s) in the two cases.