Be a Critical Thinker!

Critical thinking.  Without a doubt, you've heard this term before.  But how to actually become a critical thinker? Critical thinking is an indispensable skill in Psychology, but its also one of the hardest to teach.  Critical thinking is like a muscle - the more you practice it, the more it develops.  On this page, you'll be given a general introduction to critical thinking, while later on you'll learn some key questions to consider when evaluating research.  But don't be afraid to raise your own questions - that's what real critical thinking is all about.
Think Critically

With high-speed internet and free video sharing websites, exposure to pornography has skyrocketed.  In the last 15 years or so, it has become commonplace for teenage boys to grow up with easy access to millions of sex videos.  The consequences of regularly watching porn, especially at a young age, are still not fully understood.

Some young men feel that porn has ruined their sex lives.  There are lots of stories on the internet of men who say they are addicted to porn, and struggle with normal sex and intimacy.  Some young men say they have trouble getting aroused by a real partner, or describe an overwhelming urge to watch pornography.  In fact, there is a popular Reddit community called " No Fap ", consisting of young men who are trying to break their addiction to pornography, and warn others of its dangers.

Is internet porn really that bad?  As Psychologists, we shouldn't rely too much on a few personal experiences or anecdotal reports.  We need to carry out scientific research to investigate the matter.  So let's see what the research has to say:  Read the Esquire article titled " The Latest Science of what Internet Porn is Doing to Your Brain ".  

1.  Make a list of all the evidence that internet porn may be harmful.  Are there any flaws in these studies?  Explain them.

2.  Make another list of evidence that internet porn may, in fact, be just fine.  Note any limitations of these studies as well.

3.  What conclusions (if any) can be drawn from the existing research?

​See suggested answers at the bottom of this page
Critical thinking is all about the ability and willingness to assess claims by carefully examining the research evidence.  A claim is simply a statement asserting a truth, such as the claim that "internet porn can ruin your sex life".  Rather than being convinced by stories of people who feel that porn has damaged them, a critical thinker will demand research evidence before making any conclusions.   Moreover, a critical thinker will also evaluate the strengths and limitations of each study, reflecting on what the results of the study really tell us. Critical thinking is about looking for the flaws in any argument, considering both sides of the debate, and resisting the urge to believe something unless it is well supported by evidence.  

Critical thinking can seem challenging at times, and it is.  Its much easier to believe something because it "feels right", because its "common sense", or because the person making the claim is someone you trust.  But only critical thinking can lead you to something that is closest to the truth.  Lots of people believe all sorts of ridiculous nonsense because they fail to think critically.  Don't be like them - start thinking critically today!

To get you started on your journey to becoming a critical thinker, here are some tips to keep in mind:

1.  State the claim precisely.  For instance, the claim that "internet porn is damaging to relationships" is a very broad, imprecise claim.  There are lots of ways that porn might be damaging, so we need to narrow this claim down before we can assess the evidence.  For example, the claim that "internet porn use leads to erectile dysfunction" is much more precise.  We can then look for research studies that investigate erectile function in people who watch porn, and see what those studies tell us. 

2.  Look for evidence, not anecdotes.  Personal stories can seem very convincing.  If your best friend feels strongly that watching porn has ruined his sex life, its hard not to be convinced.  But people often feel strongly about things that turn out to be completely false.  That's why the field of Scientific Psychology is based on research studies, not personal anecdotes.  Make sure to base your conclusions on research evidence, no matter how compelling an anecdote may seem.

3.  Consider alternative explanations.  Even the best studies can produce results that are open to interpretation.  In particular, remember that a correlation between two variables can have multiple explanations.  One example is the finding, discussed in the Esquire article, that watching porn is associated with divorce.  Perhaps watching porn really did harm the relationship.  Or, perhaps people who are unhappy in their marriage, and on the verge of divorce, tend to stop having sex with each other, and turn to porn instead.  Both explanations need to be considered before making any definite conclusions.

4.  Consider flaws in the research.  No research study is perfect.  In the next few pages, you'll learn some key questions to evaluate the strengths and limitations of a research study.  In general, its best to look for consistent findings across a broad range of studies, rather than relying on a single research result.

5.  Remember that correlation does not imply causation.  At the risk of being repetitive, do keep in mind that observing a correlation between two variables does not imply that one variable is causing the other.  Many people get confused between correlation and causation, and that's one of the cardinal sins of critical thinking.  Don't fall into that trap.  For example, suppose that a correlation is found between heavy porn use and poor relationships.  Perhaps porn really does ruin relationships.  But maybe its the people who struggle with relationships that tend to watch a lot of porn in the first place. 

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A woman takes her healthy, infant son to a doctor's appointment, and the child receives a routine vaccination.  Just hours later, the injection site becomes infected.  The child cries all night, suffering from a severe fever.  A few months later, the child seems still seems distant, withdrawn and uncommunicative.  Eventually, the diagnosis comes in: severe autism.  The young boy will no longer be the same.

Such stories  have spread on the internet , and have persuaded many parents not to have their child vaccinated.  Study after study has found no link whatsoever between vaccinations and autism, but many parents remain unconvinced.  As a result, many young unimmunized children die from completely preventable diseases.

Why do you think many people believe personal anecdotes over statistical data?  Why are personal anecdotes and stories so powerful in changing people's minds?  Is it more reliable to make a decision based on personal experiences or statistical data?  Which way(s) of knowing are involved here?
Try it Out

Practice your critical thinking by evaluating one of the claims below.  Using internet sources, gather as much research evidence as you can both for and against the claim. You should give more credence to trusted sources, such as peer-reviewed research studies, or articles in well-known Science magazines.  Evaluate how good the evidence is on both sides of the debate.  Finally, state your verdict on the truth of the claim (if enough evidence exists to make a conclusion).

1.  Vaccines cause autism

2.  Playing online memory games can improve your memory

3.  Mindfulness meditation increases academic performance in schools

Think Critically

Studies suggesting porn is harmful - A study by Max Plank found that a part of the brain (associated with reward) is smaller in the brains of heavy porn users.  A study by the American Sociological Association found that couples who begin watching porn double the chance of divorce (unless they watch porn together).  However, as these studies are correlational, they don't prove that porn was the cause of the brain changes or relationship failure.

Studies suggesting that porn is not harmful - Research evidence suggests that people who watch porn regularly do not experience any loss of interest in sex.  A report in the Journal of Sexual Medicine failed to find a clear link between watching porn and erectile dysfunction.  In a 2008 Danish study, most young people reported that porn had a positive effect on their lives.

Conclusion - There isn't any evidence to draw any firm conclusions about the effects of porn.  It's likely that porn may have different effects on different people.