FALLACIES HANDOUT There are three general types of fallacies: 1. Material fallacies: errors in the process of using supporting materials as proof. 2. Logical fallacies: errors in the process of reasoning. 3. Psychological fallacies: claims that rest upon emotional appeal rather than logic and evidence. NOTE: Fallacies can be and often are persuasive. This is their key danger. I. Material fallacies A. Misuse of statistics 1. Manufactured or Questionable Statistics --stats that have been fabricated, or statistics whose validity is highly questionable because there is no reasonable method for compiling such stats, or that which is quantified is too trivial to warrant the time, effort, and resources necessary to compile accurate stats. a. "The Star Spangled Banner has been sung over 5 million times in the U.S. just this year alone.” b. Raymond Brown in his A Book of Superstitions, claims that "about $275 million in business is lost on Friday the 13th because people are afraid of the danger so they stay home.” c. "Researchers say anywhere from 1 in 10 and 1 in 100 Americans have genital herpes." (Difference between 1% and 10% of American population is enormous—stats are imprecise, untrustworthy estimates) 2. Irrelevant Statistics --stats with no direct bearing on the implied or stated claim yet are offered as evidence supporting the claim. a. "Our increasing success against the AIDS epidemic is noteworthy. We currently spend 10% more federal funds on research than last year." (Money may have been spent on worthless research--spending doesn't always produce results). b. "The average citizen is better off now than 20 years ago. Incomes for the average family of 4 have increased by 13% compared to 20 years ago." (Not constant dollars; must factor in inflation rate or this proves nothing) 3. Sample Size Inadequate or Unspecified --sample size is very small or you are left guessing what the sample size might have been. a. "Four out of five doctors recommend aspirin for headache pain." (How many doctors surveyed?) b. "80% of those surveyed support the Cable television legislation." (How many surveyed? NOTE: if only a percentage is offered without the number surveyed, bet on the sample size being inadequate) What makes an adequate sample size? a. Sample of 1000 is usually sufficient whether the survey is national, state, or local. b. Sample must be randomly selected (typically from a table of random numbers). c. Margin of error should be no more than + or - 3% to be very representative. 4. Self-selected Sample --you choose to participate in a survey, you are not selected as part of a random, representative sample. a. Local TV station KSBW conducts "call-in" polls each evening. Viewers choose to participate, usually if they have a strong motivation such as anger or a vested interest in the results being favorable to their beliefs. b. Surveys/questionnaires printed in Psychology Today or any magazine, newspaper etc. asking readers to respond. 5. Dated statistics--statistics that are not current. Statistics should be as up-to- date as possible, especially if the event, phenomenon, or situation is volatile and likely to change quickly (e.g., number of unemployed, long-term interest rates on mortgages, murder rates in various cities, international monetary exchange rates). NOTE: Some phenomena change very slowly if at all over time (e.g., deterrent effects of punishment on crime rates, percentage of U.S. population who call themselves Catholics, Protestants, etc.) requiring less attention to recency of statistics. VOLATILITY is the key factor—how quickly do things change? Recency is critical with high volatility. a. "According to a 1995 United Nations Report, the number of AIDS cases is doubling every three years." (Too old to be valuable. Substantial efforts have been made since 1995 to combat the spread of AIDS.) b. "According to the Department of Housing and Urban Development in a 2005 report to Congress, housing starts are at an all-time high in the United States." (Big recession occurred 2008-2009, significantly affecting housing starts, so statistics are dated and in this case useless except for historical comparison.) CRITERIA FOR VALID USE OF STATISTICS 1. REPRESENTATIVENESS 2. CREDIBILITY 3. RELEVANCE 4. RECENCY B. Misuse of Authority 1. Incomplete Citation -- reference to the authority is neither specific nor complete. a. Minimum requirements for "complete" citation are: 1) Qualification of authority if not immediately obvious, 2) Place of publication of quotation by authority, 3) Date of reference especially if topic is rapidly changing phenomenon. b. EXAMPLES OF INCOMPLETE CITATIONS: 1). "Dr. Charles Lamb, in last month's Men’s Health magazine argues that steroids are not harmful to athletes if used properly." (What kind of a doctor is Lamb?) 2). "Research studies indicate that ozone depletion is a serious problem." (Vague reference--which studies, when conducted and by whom? Less of a problem if prestigious authority is speaking in his/ her field of expertise and should be familiar with latest research) c. A Sample citation that is complete: SAMPLE: "According to Joan Phillips, Director of the Planning Resource Center at the University of Westchester, in her Final Report to the Board of Trustees last month, states: "Blah, blah, blah, etc., and so forth." 2. Biased Authority --special interest groups or individuals who stand to gain money, prestige, power, or influence simply by taking a certain stand on an issue or those authorities whose crusader mentality makes it improbable that disconfirming evidence on controversial claims have been examined. a. Quoting the Democratic Party Chair on the advisability of voting for Republican candidates (and vice-versa). b. Quoting representatives of the coal industry on “clean coal” 3. Authority Quoted Out of his/her Field --an expert in one field of study or endeavor is not necessarily an expert in another or even parallel field. a. "The Secretary of State assures us that the recession will be over by the middle of next year.” (Sec. of State is theoretically an expert on Foreign Relations, but that does not make him/her an expert on economic issues. Even the president on economic issues (Presidents usually have little knowledge of economics, averaging only one course during their education. They rely on the Council of Economic Advisors for help.) b. Legislators quoted on education policy. (Most legislators know little to nothing about education policy, research, etc., Having gone to school - at whatever level - does not make a person credibly knowledgeable, much less an expert, on education policies.) CRITERIA FOR VALID USE OF TESTIMONY OF AUTHORITY 1. CREDIBILITY 2. REPRESENTATIVENESS 3. RECENCY II. Logical Fallacies A. Hasty Generalization -- drawing conclusions (generalizations) from too few or atypical examples. 1. "German shepherds are mean, vicious dogs. I saw three different German shepherds on three separate occasions attack small children without provocation." 2. "All of the terrorists that attacked the World Trade Center were Arabs. Arabs are terrorists and we should ban them all from America.” (You should not base a conclusion on extreme examples) 3. Rep. Joe Wilson heckled the president by shouting “You lie.” Republicans have no sense of decorum and civility. (Don’t generalize from a single vivid example) B. False Analogy -- claim made on the basis of the similarity of two items, phenomena, etc. What is true of one is claimed to be true of the other even when a critical point of difference exists between the two things compared. 1. "We should not teach secular humanism in public schools any more than we should teach safe-cracking or arson." (Comparing crimes with a legal ideology) 2. "The success of the 40-hour work-week suggests that it should be used on farms." (Weather necessary for growing crops doesn't occur according to a time clock) C. Mistakes in Causation 1. Correlation as Causation (Post Hoc Ergo Propter Hoc) When two phenomena vary simultaneously or one follows the other, a causal linkage is asserted where known has been proven. a. "Since minority groups have been given more educational opportunities, we have had an increase in the crime rate throughout the United States. Educating minorities will simply increase crime.” b. Superstitions are based on correlation as causation fallacy--you see a black cat and you have a car accident. Black cats cause wrecks. 2. Single Cause --attributing only one cause to a complex phenomenon with many causes. NOTE: Correlation as Causation and Single Cause fallacies are mutually exclusive. An argument can’t be both because Correlation as Causation is the fallacy of asserting causation without adequate justification (merely a correlation), whereas Single Cause asserts merely one cause when many causes are likely (causation is not in doubt, only the number of causes is questioned). a. "Increasing interest rates is the cause of high inflation." (A cause but not the only or necessarily the most important cause) b. "Poor communication is the reason for the alarming increase in the divorce rate." (A cause but not the only or necessarily the most important cause) D. Criterion Fallacies (this fallacy is pervasive and manifested almost hourly, so I’ve provided extra examples.) 1. Missing Criterion -- claim requires definition of key term establishing standard for evaluating validity of claim but no definition is offered. a. "John is clearly smarter than Mary." (No way to evaluate the validity of this claim without a clear definition of what constitutes “smart") b. "Harry is a child abuser." (Must define child abuse before you can evaluate this) c. “Hunger Games is a great trilogy of movies.” (What constitutes “great?”) d. Abortion on demand is murder by request. (What are the criteria for determining “life”? What constitutes “murder?” Absent those standards/definitions being presented, the statement itself is just unsubstantiated, unpersuasive, indeed empty, verbiage.