Logic Labs Part 3

What fallacy is committed when a thinker comes to general conclusion about an entire population on the basis of a small and inadequate sample?

hasty generalization

True or False: "Critical thinking involves finding the right balance between efficiency and diligence."

True

An authority must have expertise covering the range of issues over which he or she exercises authority.

TRUE Just because someone is an expert in one area it does not mean that they are experts in all area

A representative sample is:

one that expresses the same degree and pattern of association of properties in the source population as in the target population

"Experts do disagree. When there is a clash of experts over some matter, we should always follow the word of the one with the greatest seniority." This claim is

. False Response Feedback: Seniority often decides a controversial issue in the workplace and those who have been on the job longer tend to have more say in how to proceed; but this common practice does not mean that someone with more experience is always correct.

Which of the following statements about analogical reasoning is FALSE?

Analogies are never really very strong arguments because they are only about particular things.

Consider what an education expert says about No Child Left Behind (NCLB): "Critics claim that the law's focus on complicated tallies of multiple- choice-test scores has dumbed down the curriculum, fostered a 'drill and kill' approach to teaching, mistakenly labeled successful schools as failing, driven teachers and middle-class students out of public schools and harmed special education students and English-language learners through inappropriate assessments and efforts to push out low-scoring students in order to boost scores. Indeed, recent analyses have found that rapid gains in education outcomes stimulated by reforms in the 1990s have stalled under NCLB, with math increases slowing and reading on the decline.... At base, the law has misdefined the problem. It assumes that what schools need is more carrots and sticks rather than fundamental changes." [Linda Darling-Hammond. Evaluating 'No Child Left Behind.' The Nation, May 21, 2007. Available at http://www.thenation.com/doc/20070521/darling-hammond.] What would Darling-Hammond recommend that lawmakers seeking to reform education do?

Answer: c. Define the problems facing public education more carefully to reflect those changes that need to be made most urgently. Response Feedback: This question shows how important it is to be clear about the issue under consideration. A piece of legislation can do more harm than good if it doesn't adress the real problems that need to be solved.

Assess this argument from analogy: "There are several instances of male baboons in a group under study that were less aggressive in comparison with their aggressive group leaders. When new recruits joined the troop, they came to conform to the more laid back ways of the troop. The troop continued to become more laid back. This result is from studies of a troop of baboons in Kenya. Individual humans behave in similar ways from an early age. In fact, as early as three years of age, they learn to follow rules, including learning to articulate and insist on the rules. Therefore the male baboons learned to follow rules in the very same way as young humans do."

Answer: d. weak by rule 4: presence of unexplained differences

Consider this passage on the Ohio State football scandal: "Although some sports writers say Tressel's resignation will have a ripple effect in the world of college football, Mr. Huguenin at Rivals.com disagrees. 'Frankly, I don't think it will be long-lasting. College athletics has had an extraordinary number of allegations of rules-breaking in the past 18 months, and I think much of it is shrugged off as 'Everybody does it.' I think everybody does do it, but the magnitude is the difference. There seems to be little black and white in the NCAA rule book - at least how the NCAA interprets it - and I think a lot of coaches live in those gray areas." Suppose Huguenin is correct and Tressel's resignation has had hardly any effect on college athletics. What failure of reasoning does Huguenin think is responsible?

Appeal to common practice

Which of the responses below best identifies the reasoning in the following: "Did you know that being married adds years to your life? It's really true. How do I know? Well this is the view of many people and no one has ever shown it to be wrong."

Appeal to ignorance and common belief

Which of the responses below best identifies the reasoning in the following: "No one was around when the Earth first came into existence and so no one was around to witness directly how life began. For this reason, we have no scientific evidence on which to base our beliefs about our origins. It follows that we should just choose the account that makes the most sense to us as individuals. Personally, I like to think life on Earth was planted by aliens from outer space."

Arguing from ignorance and wishful thinking

"Inductive generalizations provide irrefutable knowledge of what properties are correlated in a population among things of a certain kind."

False

True or False: "All fallacies divide neatly into mutually exclusive and jointly exhaustive categories."

False

True or False: "If there's no evidence to support a particular conclusion, then we always have good reason to believe that it must be false."

False

True or False: If an argument is valid such that it is impossible for the premises to be true and the conclusion false, then that argument cannot be an example of fallacious reasoning.

False

Relying upon observation as a source of evidence might require the use of special equipment. But it never requires special expertise in using one's own senses.

False Not everyone has the same sensory capacity and experts train their senses. A piano tuner, for example, has a more sensitive ear while a chef will have a more discriminating sense of smell.

Ordinary individuals are never experts and so never authorities.

False Ordinary individuals have all kinds of expertise! Homemakers, for example, may be experts at childcare while hobbyists may be experts in crafts.

Language that is unclear because it is imprecise is vague. All vague language is bad and should be eliminated.

False Response Feedback: Not all vague language is useless because precision is not always an option. Estimates and educated guesses are more reliable if they are not too exact.

An ambiguous term or phrase is one that has more than one meaning. An example would be "character," a word that means, among other things, a person's moral or ethical profile; a symbol; a part in a play or film; an individual who is notorious for having a distinctive personality. "Ambiguous terms or phrases are always a benefit since they allow one to say a lot of things every time that term or phrase is used." This claim is:

False Response Feedback: Sometimes ambiguous words can be used cleverly to mean many things. For example, there's Hamlet's line to Ophelia, "get thee to a nunn'ry!" Is he saying she should join a convent? Or is he saying she should become a w*** since "nunnery" was used at that time to mean "brothel" as well as convent? Shakespeare scholars continue to disagree. When it comes to thinking critically, it is best to be as precise as possible about the meanings of the words we use.

Which of the responses below best identifies the reasoning in the following: "As I see it, we can either fund the police department or we can continue to fund the city arts council. But which one do we need more? Do we really want to risk the safety of our citizens for the sake of a cultural institution with dubious value? Only a small fraction of the population even takes advantage of the arts events that the council supports--but everybody needs police protection."

False dilemma

Which of the responses below best identifies the reasoning in the following: "If human beings are not made in the image of God, and if the entire cosmos is nothing more than a freakish accident, morality is nothing but a mirage, and human beings—cosmic accidents that we are—are free to negotiate whatever moral arrangement seems best to us at any given time. Human life has no inherent dignity, morality has no objective basis, and we are alone in the universe to eat, drink and be merry before our bones join the fossil record and we pass from existence." [J. Albert Mohler "The Origins of Life: An Evangelical Baptist View" www.NPR.org: August 8, 2005.]

False dilemma

Authorities always fully use all of their expertise when making claims in the areas of their expertise.

False. Expertise can be compromised in many ways: a well-educated person can come to a hasty conclusion if they are under pressure to say something quickly. Experts may also emphasize one conclusion over another if they have a financial stake in the outcome. For example, the designers of a new drug may emphasize those studies that show how effective their new drug is and ignore those studies that show how older drugs work just as well to treat the same condition so doctors will be less inclined to prescribe cheaper generic remedies.

"Non-experts are never good sources of evidence in assembling arguments." This statement is:

False. Non-expert testimony may be relevant. If you are making an argument about the beliefs of non-experts then their input would be necessary. For example, what evidence would we need to decide whether the following sentence is true or false: "Most people do not understand global warming."

Which of the following is NOT true of an inductive argument?

If the premises are true then the conclusion must be true.

"Bias results from being inclined against someone or some view and so failing to be open to what might be relevant considerations concerning the issue under discussion. For this reason, the critical thinker will take any and all views that may be offered as evidence when thinking about some issue." Is this argument correct?

Partially correct: The definition of bias is correct but the inference from it is wrong. Response Feedback: Critical thinkers are like connoisseurs who have highly developed taste in art or food: they prefer good arguments to bad ones and are not satisfied with unreliable evidence. For this reason, they don't take any and all views offered equally seriously. Being biased is rejecting views outright because they conflict with one's personal preferences, e.g., "The proposed sewer project is a bad idea because it would inconvenience me" or "The proposed sewer project is a good idea because it would increase my property value." Neither argument is any good because sewer projects connect homes together. Whether a project is worth pursuing should not be based on how one home is affected by the project.

Consider the abstract of the 2001 paper cited in the previous question: "Three experiments investigated the malleability of perceived plausibility and the subjective likelihood of occurrence of plausible and implausible events among participants who had no recollection of experiencing them. In Experiment 1, a plausibility-enhancing manipulation (reading accounts of the occurrence of events) combined with a personalized suggestion increased the perceived plausibility of the implausible event, as well as participants' ratings of the likelihood that they had experienced it. Plausibility and likelihood ratings were uncorrelated. Subsequent studies showed that the plausibility manipulation alone was sufficient to increase likelihood ratings but only if the accounts that participants read were set in a contemporary context. These data suggest that false autobiographical beliefs can be induced in clinical and forensic contexts even for initially implausible events." What conclusion can we draw from this paragraph?

People can develop false memories about highly unlikely events in their own past, in both research and real-life situations, if their perception of the plausibility of these events is increased via personalized suggestions.

Which of the following is a fallacy of fairness, rather than openness, as defined in this class?

Straw Man Response Feedback: Bias, ad hominem, and poisoning the well all take place before the other side has even had a chance to formulate their position, reflecting a failure to be open to debate. The straw man pretends to take the other side seriously, but unfairly represents the other side as weak and insubstantial--like a man made of straw.

What fallacy is involved when someone deliberately introduces irrelevant concerns in order to distract people from the real issue under consideration?

Red Herring

In scientific reasoning, a sample is:

Selected Answer: a. a selection of cases chosen to represent the degree and forms of association among properties that occur in the target population

Which fallacy asserts that someone's views are not to be taken seriously because they conflict with or contradict previous views that the same person used to hold at an earlier time?

Selected Answer: a. hearsay

True or False: Scientists and other experts, unlike ordinary people, are able to overcome the instinctive biases to which human beings are subject, such as preferring confirming evidence and not seeing meaningful patterns in random data.

Selected Answer: b. False Answer Feedback: This is false--as the example in the previous question shows. Even scientists are subject to "seeing faces" in ambiguous data and are more favorably inclined toward data that confirms, rather than disconfirms, their hypotheses.

The environmentalists replied to the ranchers who graze herds in Yellowstone Park that it is up to the ranchers to prove that the ecosystem would stabilize even when wolves are no longer present. The ranchers said the environmentalists were the ones with the burden of proof since they were the ones advocating some form of human intervention to reintroduce the wolves. The environmentalists accused the ranchers of trying to shift the burden of proof. Yellowstone is part of the National Parks system and is, thus, required to keep things in their natural state. Who really has the burden of proof on this issue?

The ranchers have the burden of proof because the park was required by federal law to keep things natural and the wolves were there first in addition to being a keystone species.

To determine how many patients follow their doctor's advice, researchers asked 200 randomly chosen doctors to put the question to their patients. Of the 4,000 patients surveyed, 95% said that they did indeed follow their doctor's advice. Thus we can conclude that at least 90% of all patients follow the advice of their physician. Are there any problems with this reasoning?

The sample is biased because people who do not follow their doctor's advice are not likely to admit that fact to their own physician.

Identify the dominant fallacy committed by someone trying to sell her house: "You know we here in Happyville welcome anyone into our community. But at the same time we recognize that some people are just not going to fit in here. In this community we understand why folks from a different culture, for example, recent immigrants, do not belong in places like Happyville and so those people would be better off if they could be prevented from buying property here."

This a case of prejudice

Biologists agree that North American wolves are a keystone species—a species that is so important to an ecosystem that if they were to become extinct, their ecosystems would collapse. When wolves were taken out of Yellowstone Park, the population of deer, antelope and elk—the primary food sources of the wolves—exploded so that people either had to feed the hoof-stock or witness mass starvation herd death. In the 1990s, wolves were re-introduced into the park (Yellowstone Parks Wolf Reintroduction ). Ranchers opposed the re-introduction of wolves because they feared the wolves would eat their cattle while they grazed on federal lands, leased from the government. While they agreed that wolves were important to the Yellowstone ecosystem, they denied that the ecosystem was at risk without wolves because people could simply balance the system by feeding the hoof-stock. What fallacy does the rancher's reasoning involve?

This involves the straw man fallacy.

"An argument from analogy proceeds from a particular case or cases to another particular case."

True

When experts disagree this is a good reason for remaining skeptical about the truth of what any of the disagreeing experts is claiming, at least until the dispute can be settled.

True Response Feedback: When the disagreement is genuine, then there is good reason for non-experts to remain skeptical. Beware "manufactured dissent" however! Sometimes people will try to make it appear as if there are differences of opinion when, in fact, the experts do agree. So, for example, the tobacco industry tried to make it appear that experts disagreed about whether or not smoking was harmful to people's health long after medical opinion was convinced that smoking is unhealthy. What issues can you think of today where some people try to create the appearance of disagreement among experts where there really isn't any?

Questions about personal preferences are rarely settled by appeals to impartial authority.

True Response Feedback: Yes--if you and a friend were to disagree about the merits of a particular movie or band, you would not settle your dispute by appealing to professional critics, IMDb, or Billboard magazine. Sometimes, in matters of taste, you have to agree to disagree!

Which of the responses below best identifies the reasoning in the following: "You know, I read somewhere online that Americans obsess about their health. If they spent less time worrying and more time having fun, they would be much happier. For this reason, I am going to be much happier eating those foods I enjoy and not fretting about whether they're wholesome."

Unsubstantiated evidence

According to Elizabeth Loftus, people can be made to believe that they have had experiences that they have not had. In an article from 2001, she and her colleagues write: "Many studies have shown that people can be led to believe that they experienced events, when in fact, they did not. People have been led to believe that they were born left-handed (Kelley, Amodio, & Lindsay, 1996), that they spilled punch at a wedding (Hyman, Husband & Billings, 1995), that they broke a window with their hand (Garry, Manning, Loftus, & Sherman, 1996; Heaps & Nash, 1999), or that they got lost before age 3 (Mazzoni, Loftus, Seitz, & Lynn, 1999). These and other examples indicate how powerful suggestions can be in terms of making people believe that they had childhood experiences that they probably did not have." Changing Beliefs About Implausible Autobiographical Events: A Little Plausibility Goes a Long Way . What does their research suggest to the critical thinker about the value of eyewitness testimony in a courtroom?

We need to improve forensic procedures that deal with witnesses in an effort to increase the reliability of courtroom testimony and decrease the degree to which witnesses are led to form false beliefs.

Which of the responses below best identifies the reasoning in the following: "If evolution really did happen, and life on Earth has been slowly evolving for millions of years, then I would have to re-think a lot of my beliefs about my religion and my relationship to God. But that would be a lot of hard work and, in fact, I'm scared that if people really are related to other primates, then that would mean that I'm just a mortal animal without an immortal soul. For these reasons, evolution could not have happened, life on Earth has not been evolving for millions of years and people are not related to other primates."

Wishful thinking

Which of the responses below best identifies the reasoning in the following: "The whole concept of a healthy life style choice seems bogus. To talk this way sounds like there is a clear line between healthy and unhealthy life styles. But of course this is not true and it certainly is not the same for all of us. Life is too complex to divide neatly into healthy or unhealthy styles of living. Life is to be enjoyed. Why waste time worrying over whether our style of living is healthy or not? Let's just eat, drink and be merry and enjoy life as much as possible while we can."

Wishful thinking and line-drawing

"National booksellers now invite online reviews by readers. Everyone should take advantage of this and buy those books that receive the best reader reviews. Online reviews are the best way to decide what books to buy. Readers are the real authorities." Is this a correct or acceptable appeal to authority?

Yes

How would you assess the following argument from analogy? "Everyone I know who drives a Subaru really likes their car. My great aunt, who live in the mountains, enjoys her Outback while my young friend, who lives in Maryland and commutes to DC, appreciates her Impreza. My sister and her family are pleased with their Forester. For these reasons, if you are thinking of getting a new car, you should consider getting a Subaru."

c. strong by rule 3: diversity of cases

A stratified sample is:

a sample having the same proportion of the differences that might make a difference to the correlation of interest, as there is a proportion of cases of such differences in the total population

Which of the responses below best identifies the reasoning in the following: "No I have not made any end of life arrangements. Perhaps I should, but it all seems so hopeless. You don't save anything on mortuary expenses. You don't know who among your close friends is going to outlive you and so who you should ask to deliver your eulogy. You don't know where it will happen or how so what kind of plans can you really make anyway? Whenever I think about getting serious about this issue, I get so sad. I just know that somehow, it will all work out just fine, whether I make any arrangements or not."

a. The fallacy of wishful thinking

Making and assessing arguments is not which of the following:

committed to not questioning previously held beliefs Response Feedback: One of the hallmarks of a critical thinker is the capacity to revise or update one's beleifs in light of new evidence.

When different types of animals develop alongside each other, or co-evolve, insects and plants, predator and prey can become so interdependent that their ability to survive without each other is limited. For this reason, keystone species are defined as those whose presence is essential to holding an ecosystem in balance ( The Environmental Role of a Keystone Species .) If global climate change were to destroy keystone species it could lead entire ecosystems to collapse, including those ecosystems on which human life depends. Those who oppose legislation intended to slow down climate change say there is insufficient evidence. They say we are in a cycle of warming now and soon we will be in a cycle of cooling. Perhaps these cycles have more to do with solar activity than anything we do. In light of what is said in the lecture about the burden of proof, which group carries the greatest burden: Those who favor new laws to slow global warming? Or those who think that, since global warming is not proven for sure, it's not an issue we need to address via legislation?

b. Those who suggest that global warming is not proven for sure so we can ignore it

"MacIntyre is an official scotch whiskey taster for a world renowned distillery. Using the standards of the industry, she is asked to grade a number of scotch whiskeys in an annual competition. Trying her best she narrows it down to two she thinks could be number 1, then selects the Bavarian single malt over the Scottish. Later it is discovered that she had a cold when she did the taste test and that all of the entries in the contest had an unusual taste so she said that in her view any of them could have won the contest." On the basis of this description of the case, what should the contest sponsors and awards committee do?

b. not award the prize to any of the whiskeys on the basis of MacIntyre's decision since the judge could not have used her expertise. If a decision is needed, a new tasting is needed. Response Feedback: This question asks you to consider that sometimes, even in a matter of taste, there can be expert opinions. However, sometimes even the judgment of experts can be compromised by circumstance.

Assess this argument from analogy: "Individual chimpanzees are like individual humans in many ways: engaging in reciprocal grooming behavior; having a social order of authority and status; intervening in and being uncomfortable in the presence of each others' disagreements or battles; and trying to make peace with each other after an altercation. Since individual humans are also capable of feeling and expressing empathy it follows that individual chimpanzees are also capable of feeling and expressing empathy."

b. strong by rule 2: extent of similarities

Participants in the study were divided into two groups, the treatment and the control group. Each member of the treatment group had a counselor who visited him frequently; was offered academic tutoring; was given medical and psychiatric help; was offered various programs like the YMCA and the Boy Scouts. Those in the control group received none of these forms of assistance but had to fill out forms along the way. Thirty years later members of the study group were located and studied in terms of health, family, work, attitudes and criminal behavior. Those in the treatment group were found to have higher stress related disease; be more likely to express alcoholism or mental illness; and were less likely to have a white-collar job and job satisfaction. These results associate which properties together:

being provided social services and assistance as a youth with doing less well in life among those in the treatment group

Consider the following reportive definition: "Books are accounts that track income and expenditures in all businesses." This definition is not good because it is:

d. too narrow Response Feedback: Yes it is too narrow because it does not include picture books or textbooks but one could, in an accounting class, stipulate that by "books" one meant account records only.

What is the overall generalization in the following passage? Williams' syndrome is a condition in which people with the condition are missing certain strings of DNA. Upon examination of people with this condition it is shown that, "this insufficiency results in people who are too nice. What's more, they can't learn not to be nice. Which is to say, someone with Williams' syndrome can learn the phrase 'Don't talk to strangers' but can't translate it into action."

c. This research posits a correlation between being too nice and missing certain strings of DNA as characteristics of Williams' syndrome

What fallacy attempts to discredit another person's conclusions by showing how their particular situation in life makes them unable to render a credible verdict on a given issue?

c. argumentum ad hominem - circumstantial Response Feedback: A common circumstantial ad hominem would be, "That candidate comes from a different faith tradition so he cannot be trusted" or "That candidate is wealthy so he does not endorse policies to support the needy."

What two particulars are compared in this analogy? Patients pick up on whether a physician is conservative or aggressive. Patients then decide whether to work with this or that doctor depending upon whether the physician is sufficiently like them. Their reasoning is: I am uncomfortable with a conservative approach to treating my loved one--or I am uncomfortable with an aggressive approach. So I base my decision on what treatment patterns to accept on the basis of how comfortable I am with the pattern. The pattern that strikes me as most like my inclinations is the one I take to be right. "People with cancer and other serious diseases can face a dizzying array of choices. Which path they take pivots on clinical facts and the dimension of character--their own and their doctor's. This applies not only to oncology but to all of medicine, a mix of science and soul." J. Groopman (2007) How Doctors Think. (New York: Houghton Mifflin), p. 259.

c. patient and physician treatment strategies

Which of the responses below best identifies the reasoning in the following: "Proponents of health-care reform like to talk about how much money we could save through preventative care. Yet, they don't seem to realize that preventative care costs money! Who is going to pay for all those screenings and tests? Do you really think we can afford to hire personal trainers for everyone in this country to help get them into shape? Even if we could afford it, I wouldn't want some government official telling me when I have to go to the gym or what I should eat for dinner."

c. The fallacy of innuendo or false suggestion

Identify the major fallacy present in the following: "You can say all you want about the fact that we are having more and more violent weather events, like Hurricane Katrina. These are just the random patterns of weather working their way out. This is not a sign of global warming, no matter what climatologists say. Those activists who want to preserve existing biodiversity and conserve ecosystems are so in love with nature they are unable to see the objective truth that everything changes whether we like or not."

c. This is a case of the fallacy of ad hominem circumstantial.

Identify the major fallacy that seems present in the following: "Some biologists say that evolution is not always gradual and slow. Sometimes there is a sudden change in a population that makes the resulting life form diverge from its ancestral form relatively quickly. But, for a long time, biologists believed that evolution was always gradual, never involving big changes across generations of organisms. For this reason, biologists who endorse punctuated equilibrium approaches to evolution should not be believed since they are just flip-flopping."

c. This passage involves the fallacy of denying reconsideration.

"If you get a good education then you will land a good job. If you get a good job, then you will make money. A counterfeiter is someone who makes money. So if you get a good education you will do a lot of counterfeiting." This argument commits what error of ambiguity:

equivocation Here, the equivocation surrounds the two meanings of "to make money" namely, "to earn a salary" and "to print banknotes on paper."

What fallacy does this passage commit: "In 2006, Floyd Landis had his Tour de France victory taken away from him on grounds that he was using banned performance enhancing substances. Since Landis was taking these illegal drugs, we can conclude that everyone on the Phonak Hearing Systems pro cycling team was also doping at that time."

fallacy of compostion

Which of the following does NOT contribute to the strength of an argument from analogy?

d. The proliferation of unexplained differences between the objects compared.

Consider this passage based on an interview with an actor as part of his publicity tour in support of his new film Anonymous wherein he plays an aristocrat, the Earl of Oxford, as the true author of Shakespeare's plays and poems: "There is no convincing evidence that William Shakespeare of Stratford or the Earl of Oxford or anyone wrote this huge and beautiful body of work. The question that is intriguing to us is who wrote these magnificent works? That's what is important. Our film, Anonymous, raises a question and creates a debate. Debate is very important around something so substantial as who wrote the complete works of Shakespeare because these works have been so influential in our culture. Whoever the author of these plays was would be proud of what we are doing." What fallacy or fallacies does this passage commit

d. all of the above

Consider this passage: Cancer treatments fall into two groups: (1) conservative treatment dictated by research indicating the likelihood of a remission in the face of certain forms of treatment or (2) aggressive treatment that might be experimental but seems promising for a particular individual. Arguments for (1) rely on similarities between this patient and a variety of others who were treated in certain ways with certain outcomes. The argument for conservative treatments generally go like this: patient P is the same in relevant ways (symptoms, physical condition, kind of cancer, stage of cancer) as others who also did well under treatment form T. Therefore this patient should receive treatment form T. How would you assess arguments for conservative treatments?

d. all of the above

Consider the following argument: "Sex education can result in young adults delaying first intercourse or, if they are already sexually active, in using contraception. Virtually all studies conclude that sex education does not lead to earlier or increased sexual activity. 'Youth are interested in sex because of biological reasons, hormones,' says Dr. Cynthia Waszak, an FHI [Family Health International] senior scientist who focuses on adolescent health. 'Suggestions about sex in music, radio, advertisements, films and television reinforce that interest. Kids talk about sex and have questions about it. We should find ways to give youth the right information so they can make better, informed decisions about their sexual behavior.'" What does Dr. Waszak believe is the primary cause of adolescent interest in sexual activity?

d. biological reasons, such as hormonal changes Response Feedback: This expert claims that teen interest in sex is caused by nature and reinforced by culture.

The research for the next three questions is summarized in Michael S. Gazzaniga (1992). Nature's Mind: The Biological Roots of Thinking, Emotions, Sexuality, Language and Intelligence. (New York: Basic Books.) "Most noteworthy is the Cambridge-Somerville Youth Study implemented in 1939, which was intended to be a controlled study advocating social support in an effort to prevent delinquency. The participants, seven hundred boys from urban areas of Massachusetts, were carefully matched and then randomly divided into a treatment group and a control group" (p. 198). The boys in the sample were all delinquents because the researchers wanted to focus on boys who were the same in ways they thought relevant to the information they wished to gain. In terms relevant to the study of reasoning to a generalization from a sample, this study's sample was:

homogenous

What fallacy does this passage commit? "Those who favor restrictions on gun ownership like to point out how gun possession has declined in response to recent legislation. However, there are many reasons to doubt that gun ownership has really declined, despite what the studies show. First, there are purely practical motivations for a respondent to deliberately conceal firearm ownership, such as the concern that the caller may be a potential burglar. Second, criminals are deterred from trespassing and burgling a person's home when they have reason to believe their potential victims are armed."

inconsistent premises

"Inductive reasoning allows us to ______." Which of the following does NOT go in this blank?

infer a conclusion with certainty or no fear of falsification

Consider the following passage about the Dunning-Kruger effect wherein novices are more likely to overestimate their skills than experts: "The more skilled you are, the more practice you've put in, the more experience you have, the better you can compare yourself to others. As you strive to improve, you begin to better understand where you need work. You start to see the complexity and nuance; you discover masters of your craft and compare yourself to them and see where you are lacking. On the other hand, the less skilled you are, the less practice you've put in and the fewer experiences you have, the worse you are at comparing yourself to others on certain tasks. Whether it's playing guitar or writing short stories or telling jokes or taking photos (or writing blog posts) - whatever - amateurs are far more likely to think they are experts than actual experts are. Education is as much about learning what you don't know as it is about adding to what you do." Does this passage commit a fallacy? If so, which one?

no fallacy

What fallacy does this passage taken from a Scientific American article by Michael Shermer commit? "Rarely do any of us sit down before a table of facts, weigh them pro and con, and choose the most logical and rational explanation, regardless of what we previously believed. Most of us, most of the time, come to our beliefs for a variety of reasons having little to do with empirical evidence and logical reasoning. Rather, such variables as genetic predisposition, parental predilection, sibling influence, peer pressure, educational experience and life impressions all shape the personality preferences that, in conjunction with numerous social and cultural influences, lead us to our beliefs. We then sort through the body of data and select those that most confirm what we already believe, and ignore or rationalize away those that do not."

no fallacy

A random sample is:

one that is constructed in such a way that all members of the target population have an equally likely chance of being included in the source population

A biased sample is:

one that selects members of the source population in a way that fails to reveal the true degree or patterns of association of those properties in the target population

What fallacy would a person making this proposal be committing? "As chief executive officer, I move that we no longer support funding of this particular charity. All those who disagree with my decision, please indicate so by saying, 'I resign.'"

scare tactics

To gather evidence efficiently, we need to be committed to all of the following except:

the conclusion we expect the evidence to eventually support Response Feedback: Of course we often have a conclusion in mind when we start out looking for evidence. Suppose you are trying to determine what kinds of foods are healthy. You cannot first assume your favorite foods are healthy and then look for evidence to support that conclusion!

What is the TARGET in this argument from analogy? "The world is like an living organism and, for this reason, the world must have a soul."

the world

Consider the following reportive definition: "Banks are physical structures that enclose and protect valuables." This definition is not good because it is:

too broad and too narrow Response Feedback: It is too narrow because a bank does not have to be a physical structure in order to be a financial institution. It is too broad because many physical structures, such as homes, protect valuables.

Reportive definitions are good when the definiens, or set of defining words, give all and only those conditions for the correct use of the term being defined, the definiendum. Reportive definitions that fail to draw the correct boundaries are:

too broad or too narrow Response Feedback: A definition is too broad when it includes too much and too narrow when the definiendum leaves things out that belong to the definiens.

What is the SOURCE in this argument from analogy? "Ducks are a lot like turkeys. They are both birds with useful feathers that can be hunted in the wild. Since turkeys make excellent Thanksgiving meals, it follows ducks would make excellent Thanksgiving meals also."

turkeys

Assess this argument by analogy: Douglas Hofstadter tries to understand thought as bringing together a variety of beliefs, questions, patterns of reasoning and other forms of intelligence into a collective behavior, like the formation of fish into schools that swim as one unit, or like crowds at a show. Audiences are composed of individuals, "however, they do have one thing in common: they are all there, physically, listening to the same performer, and so they are influencing each other whenever they laugh at her jokes or applaud her, or encourage her or seem impatient in any way. Such collective modes tend to lock in very quickly, to create self-reinforcing loops of interaction between performer and audience" (p. 791). Suppose we look at learning sentential logic. We bring together new terms like WFF and tautology; we learn how to construct truth tables; we learn rules like Modus Ponens and Modus Tollens. Students attend to different problems just as the audience attends to different parts in the performance. Soon these terms, rules, and skills all come together. There is an "Aha!" moment when the meaning of formal logic clicks. Therefore, learning logic is a kind of crowd behavior linking a number of aspects of our intelligence.

weak by rule 4: presence of unexplained differences

"Over the past 70 years, the team found that about one-third of the measuring stations in its global sample indicated cooling trends. Two-thirds showed warming trends, with warm regions more than offsetting cool regions in developing a global average. Money for the new study, dubbed the Berkeley Earth Surface Temperature project, came from five foundations, including one established by Microsoft founder Bill Gates and another from the Charles Koch Charitable Foundation, widely seen as a source of money for conservative organizations and initiatives that have fought efforts to curb greenhouse-gas emissions." Does the fact that this study was funded by a variety of sources strengthen its credibility or weaken its claim to expertise?

yes, the variety of funding sources strengthens the credibility