Suggested price:   3¢ to 5¢ per word
Location:  Adrian, MI
  • 0
  • 0
  • 100%
  • 6.3%
  • 0%
  • 6.2%
  • 0%


I am a Professor Emeritus in the Psychology Department at Adrian College. I taught psychology for 34 years. I am married to a retired middle school counselor. I have three children, all of whom (including their spouses) are in education, with one exception. I like to travel, do fine art photography, and write. I grew up in New England until I was 18 and then spent 12 years in California .

EDUCATION:  Ph.D. from Wayne State University BLOG:  None provided
CERTIFICATIONS:  None provided CURRICULUM VITAE:  Must be logged in to view


  • Content Marketing
  • Education
  • Food & Drink
  • General
  • Humor
  • Local
  • Politics & Society
  • Travel

Writing Sample

Conflicts in Science and Psychology

Hank Cetola, Ph.D.

In the autumn of 1998, Colorado’s Warm Welcome program announced that parent’s of new babies would receive an audiotape of music by Mozart as part of the Warm Welcome package celebrating the birth of every Colorado baby (“Warm welcome program,” 1998).  Why Mozart?  Well, the people who ran the Warm Welcome believed that if newborns are exposed to the music of Mozart, they will learn more quickly and develop better memories and language skills.  The newborns would benefit from what has been referred to as the Mozart Effect.

The Mozart Effect is the name given to a phenomenon discovered by Gordon Shaw and his colleagues (Rauscher, Shaw, & Ky, 1993).  They did an experiment in which they had 36 college students spend 10 minutes listening to Mozart’s “Sonata for Two Pianos in D Major” (K. 448) or a relaxation tape or simply spend 10 minutes in silence.  They found that the students who had listened to Mozart did better on a spatial-temporal reasoning task than did the other students.  Further research demonstrated that listening to Mozart was superior not only to silence, but also to Albinoni’s “Adagio in G minor for Organ and Strings” (Thompson, Schellenberg, & Husain, 2001), a narrated story, and repetitive, minimalist music by Philip Glass (Rauscher & Shaw, 1998).  Rauscher and Shaw argued that spatial-temporal reasoning was required for the higher cognitive functions necessary for competence in chess, mathematics and engineering and that listening to complex musical pieces, such as Mozart’s sonata, would excite the cortical firing patterns used for math and other spatial-temporal tasks.  So, listening to Mozart improves intellectual performance, especially in math.  Or does it?

Although the Mozart Effect has been replicated in a number of studies, there are a number of studies in which the effect was not found (e.g., Steele, Bass & Crook, 1999), raising questions about the robustness of the finding.  In addition, in those studies that demonstrated an effect, questions have been raised as to whether the effect was due to Mozart’s music or something else.  For example, Thompson, Schellenberg and Husain (2001) point out that there is a crucial difference between the people who listened to Mozart in the experiments and those who sat in silence or listened to a relaxation or Philip Glass tape – differences in arousal or mood.  According to these researchers, “It is possible, then, that the Mozart effect has little to do with Mozart in particular or with music in general.  Rather, it may represent an example of enhanced performance caused by a manipulation of arousal or mood” (p. 248).  They argue that years of research has demonstrated that moderate levels of arousal can facilitate performance on many tasks, negative moods and boredom can impede performance, and positive moods can improve performance on cognitive and problem-solving tasks.  So, it may not be Mozart’s music that enhances intellectual ability after all.  The improved performance may have been due to the pleasurable and arousal properties of the music, properties shared by many other stimuli.  Thus, although the idea that “Mozart makes you smarter” received much coverage in the popular press, it turned out to be a rather controversial idea in the science of psychology.

 Controversy has always been part of science.  You are probably not familiar with most of these controversies because they usually appear only in the professional journals of the various scientific disciplines and they are usually discussed only by the scientists involved in the research.  Most of the controversies of this type deal with theoretical, conceptual, or methodological issues of interest to only those scientists who are active in the research in the field.  Typically, these disagreements among scientists are about some small details necessary for the refinement of the general theory under consideration.  This type of controversy may simply be an unavoidable side effect of the progressive nature of science.

As researchers try to discover the laws of nature, they ask many questions of the phenomena they observe and, at times, receive only partial answers.  Also, different researchers may see different relationships among the phenomena, which, obviously, might lead them to different interpretations.  Although the questions asked concern the same concept or theory, these conflicting interpretations can generate controversy within the discipline.  For example, let’s consider music again only, this time, let’s go beyond Mozart and consider music in general.  Music is pervasive.  Throughout history, music has appeared in every culture everywhere in the world.  Many people play music and virtually everyone enjoys it.  The omnipresence of music raises questions as to whether any parts of the musical experience are innate.  Is our ability to respond to music embedded in our biology?  Did it evolve?  What function does or did it serve?  Although most researchers agree that we are biologically wired to perceive and respond to music, they do not agree as to how or why a faculty for music evolved (Hauser & McDermott, 2003; Huron, 2001).

Conflicting Hypotheses

Music is a universal feature of humanity.  It is part of all cultures and societies.  It was present in ancient times and it is present today.  It emerges effortlessly in infants and we need no explicit training to appreciate it.  The music faculty appears to be innate and biologically based (Spiro, 2003).  If that is so, then a question arises as to why we evolved an ability to produce and respond to music.  Does it now, or did it in our ancient past, serve a function?  In other words, is music an adaptation that allowed us to solve challenges to our survival as individuals or as a species?  Three different answers to this question have been proposed.

Geoffrey Miller (2000), like Darwin before him, argued that music has no individual survival value.  On the contrary, if humans were concentrating on making music, listening to it, or dancing to it they would have been easy prey:  All that singing, chanting, drumming, and dancing would also announce their whereabouts quite vividly.  Also, music has other costs in the time and energy that is devoted to it.  So, with all costs and no benefit toward individual survival, why did a music faculty evolve?  Miller argued that music, instead, played a role in the survival of the species through sexual selection.  Sexual selection is a form of natural selection that focuses on successful mating (species survival) rather than individual survival.  Traits that are selected for are those that lead to successful competition for a mate.  Miller suggested that music and dance serve as fitness indicators such as aerobic fitness, physical endurance, and motor coordination.  Music and dance could also signal cognitive abilities such as learning, memory, and creativity.  Musical ability, then, would serve to announce that one is physically and cognitively fit and would make a good mate in order for offspring to have those same traits. 

A sexual selection approach has been rejected by Steven Brown (2000) and David Huron (2001) in favor of a group cohesiveness approach.  Brown argued that music promoted cooperation and cohesion in groups which lead to group fitness and, hence, survival.  Huron argued that music might have evolved as a method of social bonding.  According to this approach, music synchronized the moods of people in large groups to enable them to act in unison.  Music helped to define a sense of identity and purpose.  It helped to increase the cohesiveness of groups so they could act as a unit in those situations when group efforts were adaptive, situations such as those times when groups of individuals needed to defend themselves against other human groups.

Finally, both of these approaches have been rejected by Steven Pinker (1997).  Rather, he proposes that music serves no adaptive function at all.  Biologically, music is useless.  “It shows no signs of design for attaining a goal such as long life, grandchildren, or accurate perception and prediction of the world… music could vanish from our species and the rest of our lifestyle would be virtually unchanged” (p. 528).  He considers music to be a pleasant but fortuitous side effect of other perceptual and cognitive functions. 

As you might imagine, this controversy is pretty much of interest only to other scientists and musicologists.  My guess is that unless you have recently taken a course in biology or musicology or decided to read about the disagreement in scientific articles, you would not even be aware of the controversy.  There are other disagreements, however, that are of greater historical significance and have generated great controversy, controversy that has extended beyond the laboratory and the discussions in professional journals; controversies that involved many influential groups.  These controversies brought about massive shifts in the beliefs of most people and had a lasting effect on society.  You are probably more familiar with some of these controversies.

Conflicting Beliefs

For example, a very early scientific controversy dealt with the movements of celestial bodies.  In about the year 150 C.E., Ptolemy, an ancient Greek astronomer living in Egypt, proposed a geocentric model of the universe.  A geocentric model places the Earth at the center with the rest of the heavens revolving around it.  Some people call this view an anthropocentric model because it is a model that has the effect of placing humans at the center of the universe.  The Roman Catholic Church promoted this view because it came from an interpretation of the biblical account of creation that considered humans to be God’s special creation, and, as such, they occupied a special place in the universe; that place was at the center.  Whether we call it geocentric or anthropocentric, in this Ptolemaic universe the sun, moon, planets, and stars all revolved around the Earth.

The Ptolemaic view of the universe prevailed for almost 1500 years until a Polish astronomer Nicolas Copernicus (1473 – 1543) re-examined some data about planetary movements that had been recently gathered and discovered that the model did not describe the actual movements of the planets very well.  Because he was aware of the opposition that was surely to follow, he held off on the publication of his ideas.  Then, in 1543, just before he died, Copernicus published his heliocentric model of the solar system.  In a heliocentric model, the Earth and the other planets all revolve around the sun.  Well, not only was Copernicus correct about which model of the universe was accurate, he was right about the reaction to it.

His proposal was controversial not only among other astronomers, but also in the eyes of the Catholic Church because it was contrary to the teachings of the Bible.  After all, the Bible says that God spent five days creating the Earth and only one day on the rest of the universe, so the Earth must be the center (and most important part) of the universe or why else would God spend so much time creating it?  In fact, what Copernicus was advocating so appalled the Church that in 1616 it placed his book describing the heliocentric model on the Catholic Church's Index of Prohibited Books, not somewhere any self-respecting scientist of his day would like to find his works.

This heliocentric model remained controversial for almost a century because solid evidence supporting it was hard to come by until Galileo (1564-1642) turned his newly refined telescope to the heavens.  That’s when he observed the elusive evidence.  Not only did Galileo observe phases of the planet Venus, indicating its rotation around the sun, but also he saw that both Venus and Jupiter had moons revolving around them.  Here was strong empirical evidence supporting Copernicus.  Galileo published his findings in 1632. Well, it didn’t take long for the opposition to emerge, and they came out fighting.  Even other educated contemporaries of Galileo refused even to look through his telescope to see for themselves.  The existence of the moons around these other planets violated their theological beliefs so it was not necessary to look;  they already knew that Galileo was wrong.  In 1633 after an Inquisition, the Roman Catholic Church forced Galileo to recant his views, which he begrudgingly did.  Inquisitions can be tough on people.  As if the recantation weren’t enough, the Church then placed his publication, Dialogue on the Two Chief Systems of the World (1632), on the Index.  However, the evidence in support of a heliocentric solar system was now so overwhelming that it even began to win over members of the Church, but it still took until 1835, two hundred years later, before the Church removed books referring to the heliocentric view from the Index.

Another historical controversy familiar to most people, perhaps because it is still controversial in the non-scientific community, is the one concerning the works of Charles Darwin (1809-1882).  When he published his book, On the Origin of the Species by Means of Natural Selection in 1859 the impact of his ideas reverberated throughout the scientific community as well as throughout the general public.  Because Darwin had already presented his ideas at scientific meetings, the word about them was spreading.  People were so eager to read about his theory that all 1,500 copies of Darwin’s book sold out in the first day of publication (Berra, 2009).  The theory generated quite a stir.  Scientists were now arguing about his ideas at scientific meetings, as you might expect, but laypeople also argued about them in churches, in newspapers and magazines, and on the streets.

The controversy grew even stronger when Darwin published Descent of Man (1871) in which he argued that the same evolutionary principles that apply to the rest of the animal kingdom also apply to human beings.  Some people now thought that he really went too far.  Some still do.  Although Darwin’s theory of evolution through natural selection has received much support over the years through the research of biologists, geologists, paleontologists, anthropologists, and psychologists -- scientists who accept it as a natural law -- creationists, who reject the theory in favor of a strictly biblical account of creation, are still pursuing the controversy.  And, their voices seem to get louder every day.  As you can see, controversies can persist for generations even in the face of strong evidence.

Conflicting Perspectives

Another source of controversy in the sciences relates to the fact that different scientists approach the same problem from different perspectives and, consequently, ask different questions or interpret the evidence differently.  It should come as no surprise to find that by asking different questions, you may get different answers.  Consider, as an example, the different approaches researchers have taken to determine the causes of depression.

Some researchers, for example physiological psychologists and psychopharmacologists, apply a biological perspective to the topic.  One approach they have taken is to investigate the role played by neurotransmitters, the chemicals involved in transmitting messages between neurons.  This research has pointed to low levels of a particular neurotransmitter, serotonin, as being associated with depression.  Further research indicated that administrating drugs that stimulate the production of serotonin led to a reduction in depression.  Consequently, these scientists recommend administration of specific medications to resolve the imbalance and relieve the depression.

However, other researchers, especially those taking a cognitive or sociocultural perspective, raise the question of whether the imbalance causes the depression or whether the depression causes the imbalance.  The cognitive psychologists stress disorders of thought, the way a person interprets events, as the real problem that causes depression.  Social psychologists point to oppressive environmental conditions as causing depression.  Cognitive psychologists recommend cognitive behavioral therapy to help a depressed person reinterpret depressing thoughts.  This reinterpretation leads to relief from the depression.  Cognitive psychologists also claim that this lessening of depression has the effect of restoring any neurotransmitter imbalance.  Social psychologists, however, recommend education and social programs to change the oppressive environment.  So, each perspective has its own explanation and recommendation for improvement.  Another possibility, however, is that each perspective is supplying part of the answer.  As you can see, the answers one gets depend to a great measure on the questions one asks.  The controversy revolving around depression occurred because different researchers applied different perspectives to the same problem. 

Then again, sometimes controversies arise because the scientists are, after all, human and are subject to the same influences on their perceptions, emotions, and thinking that we all experience.  Sometimes they hold on to their ideas tenaciously even in the face of new evidence, challenging their rivals for stronger and stronger evidence.  They approach the problem with what is known as a preexisting-bias problem (Stanovich, 2010).  So the arguments go on.  Consequently, science progresses and uncovers increasingly more information about our universe and this progress often occurs because of attempts to resolve the very controversies initially generated by the same science.  Progress occurs because scientists approach controversies as challenges that motivate them to examine the questions more closely.  Controversies in science occur because scientists are not afraid to ask questions and challenge current assumptions and interpretations.  Sometimes, as we shall see, the responses to these questions and challenges go beyond reason.

At times, a topic becomes controversial because the information uncovered by the scientists may be contrary to some beliefs that other people in society hold onto steadfastly.  Many of these people are not very well aware of scientific knowledge nor do they possess very good critical thinking skills.  This problem is especially troublesome for psychology because we all believe we know something, if not a lot, about people.  After all, we have been “explaining” behavior for as long as we have been aware of other people.  We have strong emotional beliefs that are difficult to give up.  People do not go into the study of chemistry because they have strong emotional beliefs about chemicals.  So sometimes these preexisting-biases get in the way. 

This situation caused much of the controversy surrounding the ideas presented by Copernicus and Galileo in the 16th and 17th centuries and the controversy about Darwin’s ideas since the 19th century.  It is because of controversies such as these that Carl Sagan (1995) suggested that science should serve as a “candle in the dark” and help to illuminate the world of the nonscientist.  By disseminating the information and evidence they discover, scientists can educate others and help them understand and resolve these types of controversies.

Although resolving conflicts among scientists over methodological or theoretical issues can be challenging, resolving conflicts between scientists and nonscientists can be stressful.  Sometimes, such as with Darwin’s basic theory of evolution by natural selection, the conflicts among scientists can be pretty much resolved while the controversy continues unabated in the nonscientific community.  Both the controversies among scientists and those between scientists and the general population can take decades to resolve.  At times, the conflicts can become quite bitter, especially when nonscientists enter the debate with strongly held, emotional beliefs.  The fervor with which the religious community condemned Galileo and Darwin’s ideas is a prime example.  But in case you think that that type of resistance is only something of the past, let’s look at two recent examples of resistance to some scientific ideas that generated controversy:  the attacks on Elaine Showalter and Elizabeth Loftus.

Conflict Beyond Reason

Elaine Showalter is a Professor of the Humanities and a Professor of English at Princeton University.  She is best known as a feminist literary critic but she is also a medical historian.  In 1997, she published a well-researched and well-documented book, Hystories: Hysterical Epidemics and Modern Media, in which she discussed possible psychological explanations of various phenomena.  The book, which is a critical examination of why some people hold certain beliefs and suffer from certain disorders, created a commotion beyond anything that one might expect in response to a scholarly treatise.  Once her arguments got out, people felt threatened by them and started to fight back, and they fought back viciously.  What could have caused this reaction?

Showalter argued in her book, using sound reasoning and the incorporation of validated medical and psychological research, that we could better understand beliefs in things such as satanic ritual abuse and alien abduction if we considered them variations of the psychological concept of hysteria.  Hysteria is the label attached to a condition in which physical symptoms such as blindness or paralysis have no underlying physical or organic cause.  Instead, the symptoms originate in the psyche of the person suffering from them.

Similarly, Showalter proposed that there is a psychological, rather than a physical, explanation to beliefs of satanic abuse and alien abduction.  She does not deny that people believe in these phenomena.  She merely suggests that there are psychological causes to why they believe in them, causes similar to those that explained the wave of hysteria witnessed in women in the late 19th century.  So, you might ask, what’s the big fuss?  Beliefs in alien abduction and satanic ritual abuse are pretty weird.  And, after all, how many people actually believe in alien abductions and satanic ritual abuse anyway?  Why the uproar?  Why did so many people get so upset? 

Well, the negative reaction people had to Showalter’s book was not really centered on these two issues, but rather on the other things she lumped in with them:  chronic fatigue syndrome, Gulf War syndrome, and recovered memories of sexual abuse.  Her claim, based on her review of the research, was that these phenomena were similar to hysteria and, that they too, may have psychological causes – causes quite often not accepted by people displaying these symptoms.  Showalter wrote that people resist this approach because “many people still reject psychological explanations for symptoms; they believe psychosomatic disorders are illegitimate and search for physical evidence that firmly places cause and cure outside the self” (Showalter, 1997, p.4).

Showalter recognized the possibility that she might raise a few eyebrows with this radical view that psychological factors were behind these phenomena and she acknowledges such in her book:

I expect that defining recovered memory, chronic fatigue, and Gulf War syndrome as contemporary hysterias, and analyzing them on a continuum with alien abduction stories and conspiracy theories will infuriate thousands of people who believe they are suffering from unidentified organic disorders or the aftereffects of trauma.  I don't wish to offend the sufferers, but I know that many assume the term hysteria has insulting connotations (Showalter, 1997, p. 8).

What Showalter did not anticipate was the ferocity of the infuriation.  Activist members of the chronic-fatigue-syndrome community confronted her repeatedly at her public appearances attempting to discredit her by questioning her mental health and her credentials as a scholar.  At one book signing, these activists were so menacing that they forced Showalter to leave the event (Herbert, 1997).  However, as bad as this was, it got worse, as Showalter describes in the preface to the paperback edition of her book:

But I didn't predict that I would become the subject of conspiracy theories myself, that I would be accused of writing the book with secret "major corporate funding" and attacked as a "fascist" trying to "bolster a flagging career in academia."  I didn't foresee that my editors at Columbia University Press would be called “cunt- sucking maggots to let this one slither through."  I didn't anticipate that people would bombard me with hate mail, offer me the blood transfusions, advise me to get a bodyguard, threaten to rip me apart, or warn me of assassination unless I recanted.  In fact, although another year's accumulated scientific evidence has supported my arguments, the inflammatory reaction to the book from some quarters has only confirmed my analysis of hysterical epidemics of denial, projection, accusation, and blame (Showalter, 1997, p. x).

Quite a vitriolic attack against someone who is only applying critical thinking skills, raising questions about other possible explanations of observed phenomena, and examining evidence to reach a reasoned conclusion.  But, she is not alone.        We can find another example of the extremes people seem to go to when confronted with scientific evidence that contradicts a strongly held belief, especially one that also has strong emotional meaning, by looking at the responses that followed the publication of the research of Elizabeth Loftus.

Loftus is a Distinguished Professor of Psychology an Professor of Law at the University of California, Irvine.  She has been conducting research on memory for over 35 years.  Her original research on the malleability of memories, especially those of eyewitnesses, was the impetus for much more research on the topic by many other psychologists.  The results of these studies show that our memories are subject to distortion by what are often very subtle influences.

For example, Loftus and her colleagues have shown that the inclusion of post-event information (information we receive after the event occurred) into our recollection of the event can significantly distort our memory of the event.  In what has become a classic study in the memory literature, Loftus and her colleague, Guido Zanni (Loftus & Zanni, 1975), demonstrated how simply changing one word of a question could actually change what people remember about a film they saw.  Participants first viewed a film of an automobile accident.  The researchers then asked the participants one of two questions, “Did you see a broken headlight?” or “Did you see the broken headlight?”  The simple change from an indefinite article, a, to a definite article, the, led to a difference in what many of the participants reported they saw.

Those who were asked a question that contained the word, the, were far more likely to report seeing a broken headlight, even though there was no broken headlight in the film.  Loftus provided some empirical evidence that eyewitness memories are subject to distortion.  Much more research followed that supported this finding.  Because the legal profession relys so heavily on the validity of eyewitness testimony, you can probably imagine the impact.  These findings proved to be quite controversial, especially with members of the legal profession who were reluctant to believe that the memories, and consequently, the testimony of eyewitnesses, could be distorted so easily.  Gradually, as the legal profession began to pay attention to the memory research, they began to accept the fragility of eyewitness memory and they are becoming more sensitive to the wording of questions.  This change is due in no small part to the persistence of Elizabeth Loftus who has pointed out the reconstructive nature of memory while serving as an expert witness in many trials.  But the controversy surrounding the eyewitness research done by Loftus was mild compared to what followed as she extended her research on memory.

In the early 1990s, books and articles began to appear describing the discovery of “repressed memories” in therapy clients.  Clients would leave therapy with memories of childhood sexual abuse; memories that they did not have when they entered therapy.  Were these cases of recovered memories really examples of memories of actual events that were somehow “de-repressed”, or recovered, in therapy or was there another possible explanation?  That is the question that Loftus and her colleagues raised (Loftus & Ketcham, 1994).

When she began her investigation into repressed memories and their recovery, Loftus could not find any credible scientific evidence supporting the claims.  Rather than just looking at case studies reporting recovered memories, she and other memory researchers began to question the validity of these recovered memories.  Further, they proceeded to investigate whether or not they could actually produce false memories in people, not just distorted memories as they had done before.  They were very successful.  Over the course of many studies, researchers were able to make people believe that they experienced events in their lives that never occurred.

For example, they were able to convince people that they had been lost in a shopping mall at the age of five, that they had spilled punch on the parents of the bride at a wedding reception, or that they had been attacked by animals (Loftus, 2003).  This line of research led Loftus to express doubts publicly  about recovered memories.  As she began to present and publish her research findings, she started a controversy that generated much heated discussion between researchers and clinicians.  It also generated a much stronger reaction from other people.  A reaction stronger than anything Loftus expected; a reaction she was not used to.

In referring to this new type of opposition to her research, Loftus stated that it was “not the clean, intellectual type [she] was used to; it was downright dirty” (Loftus, 2003).  Loftus referred to some of this dirty fighting during an emotional acceptance speech she gave after receiving the American Psychological Society’s William James Fellow Award for Scientific Achievement in 2001.  In this speech she stated, “For more than a decade…I have been pursued by the enemies I created by virtue of my research on memory and my efforts to discredit recovered-memory therapy” (Loftus, 2001, p.14).  In that same speech she mentioned how she had received threatening letters warning her that not only was her reputation in jeopardy, but also her safety.  She told of having armed guards provided by some universities at which she spoke and of organizations being threatened with lawsuits for inviting her to speak.  She also spoke of continuing to be the target of efforts to censor her and that she could not even go into any details because of a gag order.

Her speech brought a long, standing ovation from her peers showing their support for her scientific achievement in the face of tremendous opposition.  An excerpt from her award citation reads,

Dr. Loftus has joined the ranks of other scientists, past and present, who have had the courage, inspiration, and inner strength to weather the widespread scorn and oppression that unfortunately but inevitably accompanies clear and compelling scientific data that have the effrontery to fly in the face of dearly held beliefs.

The progress of science always has and always will generate controversy.  What we need are tools that will help us understand and attempt to resolve those controversies.  Fortunately, those tools are available in the form of critical thinking guidelines.

Guidelines to Critical Thinking

            One of the common themes running through the history of controversies is that of challenging the status quo.  In each of the cases that we have reviewed thus far, the controversy started when scientists questioned assumptions, interpretations, beliefs, or theories.  Then as the controversy grew, the scientists proceeded to gather evidence in an attempt to answer the questions they raised.  They engaged in a process called the scientific method, and three fundamental characteristics at the heart of it are skepticism, being open to other interpretations and explanations, and reliance on empirical evidence.  These qualities are similar to the basics of critical thinking.

Educators have been promoting the development of critical thinking skills for many years (e.g., Brookfield, 1987; Halpern, 2003; Paul, 1984; Ruggierio, 1988; Sternberg, Roediger, & Halpern, 2007) and there are numerous definitions of critical thinking.  The definition that I find to be quite useful in examining psychological and other scientific controversies is the one developed by Carole Wade and Carol Tavris, “Critical thinking is the ability and willingness to assess claims and make objective judgments on the basis of well-supported reasons and evidence, rather than emotion and anecdote.”  (Wade & Tavris, 2008, p. 7) 

Some people have mistakenly taken two principle components of critical thinking, skepticism and openness to other explanations, to an extreme.  Critical thinkers are skeptical, but they do not just try to find flaws in arguments and leave it at that.  They go on to search for other explanations and evidence to support or refute those alternative explanations.  Merely finding flaws in everything can lead to the idea that we really can never know anything for sure and thinking that, “since all explanations are flawed, one is just as good as another.”  That approach is called radical relativism, and is an extension of postmodernism, a philosophical position that holds that social and cultural factors affect how a person observes and explains phenomena to such a degree that no single viewpoint is necessarily better than any other.  We will explore this philosophy further in the section dealing with controversies in research.  For now, let’s see how radical relativism relates to critical thinking.

Sometimes radical relativism, the idea that one person’s opinion is just as good as another’s is, mistakenly, simply considered being open-minded.  Being open-minded and viewing one person’s opinion as being just as valid as another may be true if we are talking of personal preferences.  You may like the taste of salmon better than that of beef.  Someone else may prefer the taste of beef to that of salmon.  In this case, each opinion is relative to the person doing the tasting, and, indeed, one opinion is just as good as the other.  If, however you say that salmon is healthier than beef, you have gone beyond just an opinion.  You are now espousing a belief, one that you need to support with evidence about the nutritional value of salmon compared to that of beef.  In this case, one opinion may not be just as good as another may.  The validity of the statement will depend on the evidence gathered to support it.  Consequently, we see that whether or not one viewpoint is more valid than another depends quite a bit on what, specifically, the viewpoint concerns.  Being open to alternatives does not automatically mean accepting all alternatives as equally valid.

Critical thinking, therefore, is more than simply finding flaws in explanations and being open to other possibilities.  Wade and Tavris (2008; Wade, 1997) reviewed much of the literature and condensed the critical thinking skills and attitudes identified by other writers to eight basic critical thinking guidelines:


  1. Ask questions; be willing to wonder.  This is where the skepticism comes in, skepticism in the form of extreme curiosity.  Critical thinkers question the status quo.  They aren’t satisfied with, “Well that’s just the way it is.”  They want to know why “that’s the way it is.”  They also don’t accept information just because it is an authority figure saying, “Believe me, that is the way it is.”  They aren’t afraid to question authority and, again, ask “Why?”

Critical thinkers don’t just raise questions about the world; they do it in a way that allows for many different answers, including answers that they may not have been expecting.  They are aware that the wording of the question is crucial in the type of information they will receive; and they are aware that questions sometimes contain built in assumptions that limit the type of answers that might be forthcoming.

For example, take a moment and see if you can spot some of the limiting assumptions in the following question?  “How does putting a person in a hypnotic trance improve memory?”  What assumptions did you find?  Here are two that I noticed.  First, this question assumes that hypnosis involves a trance-like state.  Hypnosis researchers do not agree that anything like a trance is involved in hypnosis.  Some theorists believe that hypnosis, rather than being caused by a trance, is due to social influences and pressures interacting with personality traits (Kirsch & Lynn, 1995).  Second, there is an additional assumption that hypnosis improves memory, an assumption that limits possible answers.  Research has shown that hypnosis can actually increase memory errors (Kihlstrom, 1994), a possibility not available as an answer due to the limiting assumption in the question.  A critical thinker would ask the question in a neutral way, a way that would not preclude other possibilities: “Can hypnosis affect memory, and if so, how?”

  1. Define your terms.  Asking a neutral question is only the first step.  Once one asks the general question it needs to be stated clearly and precisely.  Take the question on hypnosis.  If we are interested in whether or not hypnosis can affect memory, we need to define memory precisely.  Are we talking about the short-term memory of a list of items or the long-term memory of concepts?  Are we talking about remembering a learned complex physical skill like riding a bicycle, or a verbal skill like remembering a poem?  Depending on how we define the terms in our question, we may get different answers. 
  2. Examine the evidence.  Philosopher Paul Kurtz in writing about the scientific attitude has stated that a person cannot affirm any claims of truth unless he or she can support the claim by reason and evidence.  He writes that, “It is not enough to be inwardly convinced of the truth of one’s beliefs.  They must at some point be objectively verifiable by impartial investigators” (Kurtz, 1983, p. 244).  Critical thinkers do not accept arguments simply because they “just feel right.”  Neither do they necessarily accept an argument simply because it seems logical.  Although critical thinking requires logical thinking, “A belief is true if, and only if, it has been confirmed, directly or indirectly, by reference to observable evidence,” according to Kurtz (p. 245).  A critical thinker also raises questions about the accuracy of the evidence presented to support arguments as well as about the reliability of the source.
  3. Analyze assumptions and biases.  Critical thinkers try to identify and evaluate assumptions that may be imbedded in the arguments or statements they hear, or assumptions that may lie behind the arguments.  An assumption is anything that one takes  for granted as part of the argument.  An assumption is not necessarily wrong, but it is important that the assumptions in an argument are made explicit so they may be evaluated.  For example, what are the assumptions contained in the following statement?  “Abortion is wrong because it ends a human life.”  Whether you agree with abortion or not, as a critical thinker you need to identify, and possibly question, at least two assumptions: (1) that a fetus is a human life, and (2) that ending a human life is in all cases wrong.

The other part of this guideline deals with analyzing biases.  Bias occurs when we hold an assumption or belief so strongly that it prevents us from considering some of the evidence or, at the very least, prevents us from a fair consideration of the evidence.  Remember the story of Galileo?  When he used a telescope and observed the phases of Venus and the moons of Jupiter, he invited others to look through the telescope to see the evidence for themselves.  Their bias against his ideas was so strong that they refused to look through the telescope.  They stated that there was no need for them to look at anything because the fact that humans and, consequently, the Earth were the center of the universe had already been established because it was reported in the Bible.  These people were not critical thinkers.  Their bias got in the way of gathering the evidence needed to examine the argument.  As Carole Wade puts it, critical thinkers “are willing to consider evidence that contradicts their own beliefs and to examine the biases of others” (Wade, 1997, p. 155).

  1. Avoid emotional reasoning.  A critical thinker is not an unemotional person.  Quite the contrary.  Emotion plays a valuable role by allowing a person to be a critical thinker.  Without emotion, a critical thinker would not have the passion or motivation to question popular ideas or assumptions, or to raise creative alternatives and seek evidence supporting them or refuting other alternatives.  However, when it comes to evaluating arguments, a critical thinker does not let her feelings replace clear thinking.  Although we feel so comfortable and right in what we believe about an issue, we need to recognize that people who hold the opposing viewpoint feel just as comfortable and right in what they believe.

For example, many people believe that capital punishment is an effective deterrent to capital crimes such as murder.  “After all,” they reason, “if I knew that I would be executed if convicted of murdering someone I would be so scared that I just wouldn’t do it.”  The thought of dying is an emotional thought for most people.  Consequently, they believe that the threat of execution should deter anyone from committing the crime.  However, there is a growing body of evidence indicating that capital punishment is not a deterrent to violent crimes (Bailey & Peterson, 1999; Costanzo, 1997).  In fact, there is some evidence that capital punishment may actually increase the incidence of violent crime (Bowers, 1988; Cochran, Chamlin, & Seth, 1994).  No matter how strongly we feel that something is true or how strongly we want something to be true; our feelings do not make it true.  Feelings cannot substitute for a careful appraisal of both arguments and evidence.

  1. Do not oversimplify.  A critical thinker avoids either-or thinking, avoids looking at the world in terms of black or white while ignoring the many shades of gray.  For example, when trying to understand human behavior, many people get involved in the age-old debate about whether our abilities and personalities are influenced more by “nature” (genetic and biological influences) or by “nurture” (environmental, cultural, and learning influences).  Consider intelligence.  Do people vary in their intellectual ability because some people (or groups of people) are just born smarter (nature) because they inherited genes for brilliance?  Alternatively, are some people (or groups of people) more intelligent because they were raised in an enriched environment with genes having very little to do with it (nurture)?  A critical thinker would not just look for evidence supporting one side of the argument or the other.  He would examine both positions and look for a possible contribution played by each.  A critical thinker looks beyond the obvious to see what else might be part of the total picture.

Critical thinkers also avoid using overgeneralizations or argument by anecdote.  When states began to enact seatbelt laws because the research evidence showed overwhelmingly that seatbelt use saved lives and reduced serious injury, some people were opposed to them saying something to the effect of, “My cousin was in a bad car crash and had he been wearing a seatbelt he would be dead now.  So seatbelts are bad.”  Because there may be one, or even a few, cases in which a seatbelt did not help, or may even have hindered, does that mean that in all cases seatbelt use is detrimental?  Not likely.  Critical thinkers would want to examine the evidence of many cases, not just a few before drawing any conclusions.  And that is what the lawmakers did before deciding to pass the laws requiring seatbelt use.

  1. Consider other interpretations.  Not only are critical thinkers open to other reasonable explanations and interpretations of the evidence, they also actively generate as many interpretations they possibly can in order to find the one that seems to explain the phenomenon as succinctly and validly as possible.  Considering other interpretations and possibilities helps to insure that researchers do not overlook the most valid or useful one.  I once heard a story about a tractor-trailer rig that was stuck under an overpass that was a few inches shorter than the driver of the truck had expected.  The police, fire, and wrecker crews kept studying the situation trying to figure out how to free the rig.  They considered using welding torches to cut through and remove the top of the trailer.  They considered breaking apart the concrete from the overpass to free the stuck vehicle.  The debate went on until someone who was watching the whole thing said, “Why don’t you just let some air out of the tires?”  Sometimes we easily overlook the simplest explanation.  A critical thinker tries not to let that happen.
  2. Tolerate uncertainty.  Critical thinking often forces us to challenge the validity of some of our deeply held beliefs leaving us being uncertain about why things are the way they are.  Although we are willing to examine the evidence, sometimes there is not enough evidence to enable us to draw a firm conclusion.  Sometimes just when we think we understand the problem, new evidence surfaces forcing us to reconsider what we thought we understood so well.  This uncertainty is probably the most difficult and frustrating part about being a critical thinker.  Although a big part of being a critical thinker is asking questions, too often asking those questions does not bring answers, only more questions.  Rather than letting this lack of resolution frustrate them, critical thinkers accept it and are motivated to continue.

A number of years ago I gave a citation to a student who received the Outstanding Senior in Psychology Award at our college.  At the award ceremony I mentioned how I had known this student for four years and never, in my experience as a professor, had any student asked as many questions challenging assumptions, theories, and beliefs as he had.  I stated that, “Tim asked so many questions over the years that either he doesn’t quite get it or he is one of the finest critical thinkers to go through our program in many years.  I choose the latter.”  Tim has gone on to become a successful psychology professor, author, and researcher; and he continues to think critically.

Those are the eight guidelines to critical thinking.  Now, what do we do with them? How shall we apply them?  What is it that we should think about?  In general, critical thinking skills can be used everyday as we evaluate the many claims, assertions, and questions we encounter in our daily lives.  More specifically for psychology, we can think critically about, “the controversies that stimulate lively, and sometimes angry, debate in our discipline…controversies [that] make psychology fascinating” (Wade, 1997, p. 156).  That’s where this book comes in.  We will be considering some of the ideas that have proven to generate controversy in psychology and we will take a close, critical look at them. 

Some of the controversies, such as the effectiveness of different types of therapies may be relatively easy to resolve after examining the evidence.  We will find that there is more sound empirical evidence supporting one side of the controversy than the other side.  Other controversies, such as the use of deception or animals in research, may be more difficult to deal with because they involve questions of ethics and values.  We can still use the critical thinking skills on these types of issues; however, we may have to rely a bit more on reason and logic to understand them.  It is with this latter type of controversy where the guideline about tolerating uncertainty will become crucial.



Bailey, W. C., & Peterson, R. D. (1999). Capital punishment, homicide and deterrence: An assessment of the evidence. In M. D. Smith & M. A. Zahn (Eds.), Studying and preventing homicide: Issues and challenges (pp. 223-245). Thousand Oaks, CA: Sage.

Berra, T. M. (2009).  Charles Darwin: The concise story of an extraordinary man.  Baltimore: The Johns Hopkins University Press.

Bowers, W. J. (1988). The effect of executions is brutalization, not deterrence. In K. C. Haas & J. A. Inciardi (Eds.), Capital punishment: Legal and social science approaches (pp. 49-89). Newbury Park, CA: Sage.

Brookfield, S. (1987). Developing critical thinkers: Challenging adults to explore alternative ways of thinking. San Francisco: Jossey-bass.

Cochran, J. K., Chamlin, M. B., & Seth, M. (1994). Deterrence or brutalization: An impact assessment of Oklahoma's return to capital punishment. Criminology, 32, 107-134.

Costanzo, M. (1997). Just revenge: Costs and consequences of the death penalty. New York: St. Martin's Press.

Dawkins, R. (1996). The blind watchmaker. New York: W. W. Norton & Company. (Original work published 1986)

Gould, S. J. (1992). The panda's thumb. New York: Norton. (Original work published 1980)

Halpern, D. (1995). Thought and knowledge: An introduction to critical thinking (4th ed.) Mahwah, NJ: Lawrence Erlbaum Associates, Inc. Publishers.

Herbert, W. (1997, May 19). The hysteria over "Hystories.". U. S. News & World Report, 122 (19), 14.

Kihlstrom, J. F. (1994). Hypnosis, delayed recall, and the principles of memory. International Journal of Clinical and Experimental Hypnosis, 40, 337-345.

Kirsch, I., & Lynn, S. J. (1995). the altered state of hypnosis. American Psychologist, 50, 846-858.

Kurtz, P. (1983). The scientific attitude versus antiscience and pseudoscience. In P. Kurtz (Ed.), In defense of secular humanism (pp. 239-247). Buffalo, NY: Prometheus Books.

Loftus, E. (2001). When scientific evidence is the enemy. Skeptical Inquirer, 25(6), 14-15.

Loftus, E., & Ketcham, K. (1994). The myth of repressed memory. New York: St. Martin's Press.

Loftus, E., & Zanni, G. (1975). Eye witness testimony: The influence of the wording of a question. Bulletin of the Psychonomic Society, 5(1), 86-88.

Paul, R. W. (1984, September). Critical thinking: Fundamental to education for a free society. Educational Leadership, 4-14.

Ruggierio, V. R. (1988). Teaching thinking across the curriculum. New York: Harper & Row.

Sagan, C. (1995). The demon haunted world. New York: Random House.

Showalter, E. (1997). Hystories: Hysterical epidemics and modern media. New York: Columbia University Press.

Sternberg, R., Roediger, R., & Halpern, D. F. (Eds.). (2007). Critical Thinking in

            Psychology. Cambridge, MA: Cambridge University Press.

Stanovich, K. E. (2010).  How to think straight about psychology. Boston: Allyn & Bacon.

Wade, C. E. (1997). On thinking critically about introductory psychology. In R. J. Sternberg (Ed.), Teaching introductory psychology (pp. 151-162). Washington: American Psychological Association.

Wade, C. & Tavris, C (2008).  Psychology (9th ed.). Upper Saddle River, NJ: Pearson/Prentice Hall.