Assumptions Singular Explanation Numbers Misuse Bias


This is a brief paper about critical thinking. The writer makes no claims that all that is stated in the following pages will be universally accepted. However, there is some basic agreement among many who think and write about critical thinking. The following is an attempt to present this in a brief, understandable way.

No doubt there are some critical thinking skills can be applied across disciplines. However, one of the first things to understand about critical thinking is that little is possible without a certain degree of knowledge or information that is specific to the subject. One might possess a Ph.D. in Sociology but have very little knowledge of economics. This person would find it difficult to evaluate the merits of supply-side economic theory. One cannot expect to make an informed decision about the merits of a political issue unless one has a foundation, that is, some basic information or understanding of subject involved. So the first step in critical thinking involves humility. Understand that it is difficult to think critically about a topic that one knows little about.

Secondly, critical thinking requires skepticism. Information in newspapers and books is frequently incorrect, at least partially. Parents are often wrong; "experts" who have doctorates completely disagree at times. Teachers (excepting this one) are sometimes wrong. YOU ARE OFTEN WRONG. Believe it. Assume it. Critical thinkers are humble about their knowledge. They are convinced that they do not know all the answers, that their information is usually incomplete and biased. They assume the same about others.

With some humility I will attempt to give a brief definition and description of critical thinking in the social sciences.

A critical thinker in the social sciences is a person who is skeptical of simple or singular explanations to social problems, is mindful of the frequent mistakes people make in using numbers or statistics, actively looks for bias in himself and others, and searches for underlying, faulty assumptions.

Let’s examine each part of the critical thinking process described above.



This is perhaps the most critical part of examining thinking. What does the speaker or writer assume? Frequently it is assumed that people understand the same thing when a term is used. If I say "welfare" can I assume that you and I have the same understanding of the government programs that comprise it? What about the terms conservative, liberal, Christian, American?

Often beliefs that seem to be true to almost everyone in a particular group, or even in an entire country, are based on assumptions that are partially or completely false.

Many United States politicians observed elections in EL Salvador in the early 1980’s and saw that Salvadoran citizens were not prevented or coerced in voting; saw that the voting results were counted honestly, and therefore declared that the government that was elected by this process was democratic and legitimate. The U.S. government then supported this government and gave it, and the military that supported it, billions of dollars in aid. Many of the opposition groups that fought this government and military declared themselves to be socialist or Marxist. Clearly then, the United States was correct in supporting the democratic government.

The first mistake that was made here, in this writer’s opinion, was that many Americans assumed that because people could vote freely and the votes were counted correctly that there was indeed democracy. In fact, the government and the military in El Salvador systematically murdered almost anyone who spoke against them. Reporters were shot; union organizers tortured and killed; priests, nuns, teachers and others were assassinated if they spoke against the military or the government. The government controlled the newspapers, television and radio. The only thoughts or statements that they allowed to be printed, shown or spoken in the media were those that the military permitted.

Many Americans assumed that because voting was free that democracy existed. They thought that the armed opposition was part of a communist movement bent on taking over the world. Many of these assumptions were false. They went largely unexamined. The United Nations did an investigation in El Salvador to find out what really happened. Their findings were that the military and its supporters in the government had murdered approximately 10,000 people in El Salvador during the time that the United States was supplying billions of dollars in aid.

For approximately ten consecutive years during the Reagan and Bush administrations the gross national product grew. Many people therefore assumed that the economy was doing well. However, the government was going deeply into debt at the same time this economic growth was occurring. This debt would contribute to higher taxes and less government spending in succeeding administrations. Also, statistics that this author read, (hopefully accurate?!) suggested that most of the economic growth in the Eighties went to the upper-middle class and the wealthy. Most people in the United States did not fare significantly better during this time. In fact, many studies said the number of poor people in the United States increased relatively and absolutely at the same time of the supposed economic growth.

Critical thinkers often look beneath widely accepted truths and see false assumptions or ignored factors.




Often people give very simple explanations for social phenomena. Usually there are many factors that contribute to a given situation; very seldom is there just one. Also, frequently the factors that cause a certain phenomenon act upon each other in various ways. Consider, for example, the following factors: poverty, ignorance, illness, illegitimacy, malnutrition, and feelings of hopelessness. All of these factors interrelate. In a sense they all contribute to creating the others. At a given point in time, one factor might be more causal than others. For example, poor children might well be malnourished; they are then likely to be ill frequently. Sick, malnourished children often do poorly in school, become dropouts, have children without being married, and feel that they will never be able to succeed. They then find it difficult to provide good nutrition, decent guidance or motivation to their children. Their problems are often reproduced in the next generation.

It would be incorrect to say that poverty causes malnutrition. Many factors can cause malnutrition. It would be incorrect to say that ignorance causes poverty; there are many factors that can lead to poverty. One could say that poverty can be a contributing factor to malnutrition or that ignorance is often a factor related to poverty.

Below are a few statements that offer a single causal explanation for situations or conditions that are far more complex.








A frequent mistake is to ascribe causation to correlation. A relationship is causal if one factor directly brings about another, that is, the second factor could not have and would not have occurred if not for the first. As stated above, almost never is there a single cause for social phenomena.

A correlation is simply a relationship. Two things occur at the same time, or one after the other, but one does not cause the other, rather they both may be caused by other, non-related factors.

Some people say that welfare programs have caused single- parent families. They often point to statistics that show a large increase in single-parent families amongst poor people, especially black Americans, at the same time that welfare spending was increased in the United States. Some welfare programs, especially Aid to Families with Dependent Children, required that the parent be unmarried in order to qualify. Others, like Food Stamps, are income dependent; meaning that one’s income must be low enough to qualify. A single woman does not have a husband’s income to include in her application and therefore would be more likely to receive benefits. Some people argue that in order to receive more welfare benefits many women do not marry or decide to divorce.

A critical thinker is wary of simple explanations. What else could have contributed to an increase in single-parent families? Many people believe that there was a significant change during the Sixties and Seventies in the United States and other countries concerning sexual conduct and marriage. It became more acceptable to have sex outside of marriage; society also became more tolerant of divorce. The women’s movement encouraged women to find jobs, to become more independent, more self-sufficient. Another social phenomenon was occurring at the same time. Many African Americans were moving out of the South and out of rural areas and into big cities. As more poor people were moving to the cities, at the same time many well-paying, low-skill jobs were moving out of the city to the suburbs or being phased out by technology. Therefore, more poor people, especially black men, could not find jobs that paid much over minimum wage, making them more likely to be poor and less likely to be good marriage prospects.

In short, there are many possible factors that could have led to the increase in single-parent families. It is possible that the birth control devices that became increasingly available in the Sixties and Seventies had an effect on beliefs concerning sexual practices. Were the advancements in basic science responsible for the discoveries in birth control? Is it possible that the relationship between the increase in single-parent families and the concurrent increase in welfare programs is largely or mostly correlational? Were they both caused primarily by other factors? Was one partly causal of the other? These are some questions that a critical thinker might ask.



This writer has encountered many mistakes that supposedly reputable authors have made using numbers. Don’t trust teachers, or newspapers or textbooks to be correct. Often they are not. In the spring of 1997 I was reviewing two US Government textbooks; one said that the U.S. Senate had sixteen standing committees, the other said there were seventeen. They were both printed the same year (1997). One might assume that something as simple as this wouldn’t be missed. But it was. (I used the Internet and checked the Home Page of the US Senate. They said there were sixteen.)

In December of 1997 I found that an article that I was using in one of my classes said that foreign aid was only 0.012% of our budget. They misplaced the period. They meant to say 1.2% of our budget.

Frequently errors are made in reference to public opinion polls. The first mistake is to assume that the numbers cited in a poll are exactly representative of the general public. If a poll is done with scrupulous methodology, it still has a margin of error. For example, many polls say that they have a range of + or - 3pts and a reliability of 95%. This means that the numbers given in the poll have a probability of being correct 95% of the time within a range of + or - 3pts. If a person says that 52% of Americans are in favor of cutting Medicaid spending, because that is what a recent poll found, he is not being careful. The pollsters themselves would not say this. The only thing that is certain is that 52% of the people polled had this opinion. If the population being polled at the time was all adults over 18 in the United States, one might reasonably conclude that a similar percentage of this population would have answered the poll’s questions in the same way.

Secondly, poll figures are always indicative of people’s opinions in the past. For example, in early January of 1996, Bill Clinton’s approval ratings-- (percentage of people polled who thought he was doing a good or excellent job as President) were slightly over 50% in several polls. Many authors then stated in magazines and newspapers that Bill Clinton’s approval ratings were over 50%. By the time articles appeared in periodicals, the polls were over a week old. Public opinion can change rapidly. What was true a week ago may well not be true today. Issues that are perennial or long-standing such as opinions on abortion or capital punishment generally do not change quickly. However, issues that the public knows little about, such the situation in Haiti, or in Bosnia, often show significant changes in public opinion in short periods of time. This is also true of approval ratings. They can change rapidly.

Another common error is to state exact numbers when it is clearly impossible to know if the numbers are exact. Nobody knows exactly how many people live in the United States today. If someone says that there are 265 million people in the USA, he almost has to be wrong. If a Senator says that his bill will reduce spending on Medicaid by ten billion dollars over the next five years, he is saying something he cannot possibly know. It will not be exactly ten billion dollars, and it may well be considerably more or less. No one knows how many people will apply for and be accepted for Medicaid payments over the next five years. Who can predict with precision what type of illnesses these people will have or what type of medical procedures will be available or how much these treatments might cost? One can project future savings; one cannot know exactly what they will be.

Critical thinking involves checking the source of statistics or numbers. For example, one might be wise to doubt statistics provided by the AFL-CIO on the job satisfaction of union and non-union labor. The national Chamber of Commerce likewise wouldn’t generate much confidence if they commissioned a study on the same topic. One might expect that academics would be trustworthy in their use of numbers. Unfortunately this is often not so. An article in the Orlando Sentinel on Friday, May 17, 1996 stated that a sociologist named Lenore J. Weitzman: "reported that women’s households suffered a 73 percent drop in their standard of living in the first year after divorce, while men’s households enjoyed a 42 percent rise." The paper then cited another professor who took the same numbers and found that women’s households had suffered a 27 percent decrease, while men’s had increased by 10 percent. The second study came some two years after the original book came out. According to the Sentinel, the original statistics were cited in 175 newspaper articles, 348 social science articles, 250 law review articles, 24 appellate and Supreme Court cases and President Clinton’s 96 budget.

One finds with disappointing regularity that people do not add, subtract or multiply correctly. These are simple operations, but often mistakes are made. These people are very possibly incorrect in their use of numbers simply because they are not careful. Often, however, mistakes are made because a person wants the numbers to say something. Their mistakes may not be conscious or completely deliberate, but one tends to find that the mistakes made have a marked tendency to support what the authors believe or wish to convince others of.

A critical thinker treats numbers with respect and does not easily accept the numbers written or used by others as correct. The careful use of numbers can add precision to thinking and understanding. Sloppiness with numbers often means sloppiness in thinking.


It is often easy to see bias in others and difficult to see it in ourselves. In the social sciences we assume bias, that is, we understand that there is bias in all human perceptions. This doesn’t necessarily invalidate a perception or opinion, but it does mean that one must look to see how the bias might have contaminated the opinion or finding.

Often we see what we want to see; we look for what we wish to find. Our opinions or perceptions are colored not only by our experiences, but also by what is convenient for us to believe.

A common practice that we engage in is rationalization. We explain our own behavior or that of those we support in a manner that makes us or them look good. Students are likely to say that lower tuition and more public spending for education is an investment in the future of America. The fact that it directly benefits students and allows them to spend more money on other things may not be mentioned. The military says it wants more spending because it’s necessary to defend America. The fact that it will increase their salaries and make their lives a bit easier probably won’t be stated. A wealthy person is likely to say that forcing rich people to pay higher taxes will stifle initiative and eventually ruin our economy. Poor people think that the government should spend more money in social welfare programs, because a wealthy country must take care of its poor and poor people are likely to turn to crime.

In politics, the reasons given for support or opposition to a given program is often a form of rationalization. A Republican Congressperson representing a wealthy suburban constituency is likely to support a cut in welfare payments and food stamps. If you ask him why, he might well say that there is evidence of fraud in these programs and that these programs foster laziness and dependency, things that are destroying what America stands for. There is probably an element of truth in what he says. However, it is very possible that since very few people in his district benefit directly from welfare and food stamps they see little need for it and vote for people who share their ideas.

A Congresswoman representing Harlem is likely to support affirmative action programs and say that they have greatly contributed to creating opportunity for ethnic minorities and women. Again, there is probably truth in what she says. However, it is very likely that many people she represents have directly benefited from affirmative action programs and it is clearly in their direct economic interest that these programs continue to exist.

Business groups believe if they can pay lower wages and less tax they can make increased profits, employ more people, invest in new business ventures and increase production. Unions believe that if employees are paid good salaries, the workers will work harder, spend more money, and therefor increase business productivity and sales. This will then enable businesses to hire more workers at higher salaries.

A critical thinker looks for bias, understands that it motivates much reasoning and contaminates many arguments.

In summary, critical thinkers understand that social problems seldom have simple, singular solutions, are skeptical of the accuracy of statistics or numbers, assume that bias is present in most human opinions or beliefs, and look for faulty assumptions that often underlie many ideas.