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  • Can week-old pizza cause psychedelic hallucinations? Does coffee make you smarter? Or does it just

  • make you do dumb stuff faster?

  • Like a bunch of psychology itself, questions like this can seem pretty intuitive. I mean,

  • people may not be the easiest organisms to understand, but you're a person, right? So

  • you must be qualified to draw, like, some conclusions about other people and what makes

  • them tick.

  • But it's important to realize that your intuition isn't always right. In fact, sometimes it

  • is exactly wrong, and we tend to grossly underestimate the dangers of false intuition. If you have

  • an idea about a person and their behavior that turns out to be right, that reinforces

  • your trust in your intuition. Like if one of my buddies, Bob, begins eating that deep-dish

  • pizza that's been in the fridge for the past week but he eats it anyway and soon starts

  • to wig out, I'll say "Dude, I told you so". But if I'm wrong and he's totally fine, I

  • probably won't even think about it ever again.

  • This is known as 'Hindsight Bias" or the "I-Knew-It-All-Along" phenomenon. This doesn't mean the common sense

  • is wrong, it just means that our intuitive sense more easily describes what just happened,

  • than what will happen in the future. Another reason you can't blindly trust your intuition

  • is your natural tendency toward overconfidence. Sometimes, you just really, really feel like

  • you're right about people when actually you're really, really wrong. We've all been there.

  • We also tend to perceive order in random events, which can lead to false assumptions. For example,

  • if you flip a coin five times you have equal chances of getting all tails as you do getting

  • alternating heads and tails. But we see the series of five tails as something unusual,

  • as a streak, and thus giving that result some kind of meaning that it very definitely does

  • not have.

  • That is why we have the methods and safe-guards of psychological research and experimentation,

  • and the glorious process of scientific inquiry. They help us to get around these problems

  • and basically save the study of our minds from the stupidity of our minds. So I hope

  • that it won't be a spoiler if I tell you now that pizza won't make you trip, and coffee

  • doesn't make you smart. Sorry.

  • [Intro]

  • In most ways psychological research is no different than any other scientific discipline,

  • like step one is always figuring out how to ask general questions about your subject and

  • turn them into measurable, testable propositions. This is called operationalizing your questions.

  • So you know how the scientific method works -- it starts with a question and a theory,

  • and I don't mean theory in the sense of like, a hunch that say, a quad-shot of espresso

  • makes you think better. Instead, in science a theory is what explains and organizes lots

  • of different observations and predicts outcomes. And when you come up with a testable prediction,

  • that's your hypothesis.

  • Once your theory and hypothesis are in place, you need a clear and common language to report

  • them with, so for example, defining exactly what you mean by "thinking better" with your

  • espresso hypothesis will allow other researchers to replicate the experiment. And replication

  • is key. You can watch a person exhibit a certain behavior once, and it won't prove very much,

  • but if you keep getting consistent results, even as you change subjects or situations,

  • you're probably on to something.

  • This is a problem with one popular type of psychological research: case studies, which

  • take an in-depth look at one individual. Case studies can sometimes be misleading, because

  • by their nature, they can't be replicated, so they run the risk of over-generalizing.

  • Still, they're good at showing us what CAN happen, and end up framing questions for more

  • extensive and generalizable studies. They're also often memorable and a great story telling

  • device psychologists use to observe and describe behavior. Like, say the smell of coffee makes

  • Carl suddenly anxious and irritable -- that obviously doesn't mean that it has that same

  • effect on everyone. In fact, Carl has terrible memories associated with that smell, and so

  • his case is actually quite rare. Poor Carl. But you would still have to look at lots of

  • other cases to determine that conclusively.

  • Another popular method of psychological research is naturalistic observation, where researchers

  • simply watch behavior in a natural environment, whether that's chimps poking ant-hills in

  • the jungle, kids clowning in a classroom or drunk dudes yelling at soccer games. The idea

  • is to let the subjects just do their thing without trying to manipulate or control the

  • situation. So yeah, basically just spying on people. Like case studies, naturalistic

  • observations are great at describing behavior, but they're very limited in explaining it.

  • Psychologists can also collect behavioral data using surveys or interviews, asking people

  • to report their opinions and behaviors. Sexuality researcher Alfred Kinsey famously used this

  • technique when he surveyed thousands of men and women on their sexual history and published

  • his findings in a pair of revolutionary texts, Sexual Behavior in the Human Male and Female

  • respectively.

  • Surveys are a great way to access consciously held attitudes and beliefs, but how to ask

  • the questions can be tricky; subtle word choices can influence results. For example more forceful

  • words like "ban" or "censor" may elicit different reactions than "limit" or "not allow". Asking

  • "Do you believe in space aliens?" is a much different question than "Do you think that

  • there is intelligent life somewhere else in the universe?" It's the same question, but

  • in the first the subject might assume you mean aliens visiting earth, and making crop

  • circles and abducting people and poking them.

  • And if how you phrase surveys is important, so is who you ask. I could ask a room full

  • of students at a pacifist club meeting what they think about arms control, but the result

  • wouldn't be a representative measure of where students stand, because there's a pretty clear

  • sampling bias at work here. To fairly represent a population, I'd need to get a random sample

  • where all members of the target group, in this case students, had an equal chance of

  • being selected to answer the question.

  • So once you've described behavior with surveys, case studies, or naturalistic observation,

  • you can start making sense out of it, and even predict future behavior. One way to do

  • that is to look at one trait or behavior is related to another, or how they correlate.

  • So let's get back to my buddy Bob who seems to think that his refrigerator is actually

  • some kind of time machine that can preserve food indefinitely. Let's say that Bob has

  • just tucked into a lunch of questionable leftovers, pizza that may very well have had a little

  • bit of fungus on it. But he was hungry, and lazy, and so he doused it in Sriracha. Suddenly,

  • he starts seeing things: green armadillos with laser beam eyes.

  • From here we could deduce that eating unknown fungus predicts hallucination, that's a correlation.

  • But correlation is not causation. Yes, it makes sense that eating questionable fungus

  • would cause hallucinations, but it's possible that Bob was already on the verge of a psychotic

  • episode, and those fuzzy leftovers were actually benign. Or there could be an entirely different

  • factor involved, like maybe he hadn't slept in 72 hours, or had an intense migraine coming

  • on, and one of those factors caused his hallucinations. It's tempting to draw conclusions from correlations,

  • but it's super-important to remember that correlations predict the possibility of cause-and-effect

  • relationships; they cannot prove them.

  • So we've talked about how to describe behavior without manipulating it and how to make connections

  • and predictions from those findings. But that can only take you so far; to really get to

  • the bottom of cause-and-effect behaviors, you're gonna have to start experimenting.

  • Experiments allow investigators to isolate different effects by manipulating an independent

  • variable, and keeping all other variables constant, or as constant as you can. This

  • means that they need at least two groups: the experimental group, which is gonna get

  • messed with, and the control group, which is not gonna get messed with.

  • Just as surveys use random samples, experimental researchers need to randomly assign participants

  • to each group to minimize potential confounding variables, or outside factors that may skew

  • the results. You don't want all grumpy teenagers in one group and all wealthy Japanese surfers

  • in the other; they gotta mingle.

  • Now sometimes one or both groups are not informed about what's actually being tested. For example,

  • researchers can test how substances effect people by comparing their effects to placebos,

  • or inert substances. And often, the researchers themselves don't know which group is experimental

  • and which is control, so they don't unintentionally influence the results through their own behavior,

  • in which case it's called, you guessed it, a double blind procedure.

  • So let's put these ideas into practice in our own little experiment. Like all good work,

  • it starts with a question. So the other day my friend Bernice and I were debating. We

  • were debating caffeine's effect on the brain. Personally, she convinced that coffee helps

  • her focus and think better, but I get all jittery like a caged meerkat and can't focus

  • on anything. And because we know that overconfidence can lead you to believe things that are not

  • true, we decided to use some critical thinking.

  • So let's figure out our question: "Do humans solve problems faster when given caffeine?"

  • Now we gotta boil that down into a testable prediction. Remember: keep it clear, simple,

  • and eloquent so that it can be replicated. "Caffeine makes me smarter" is not a great

  • hypothesis. A better one would be, say, "Adult humans given caffeine will navigate a maze

  • faster than humans not given caffeine." The caffeine dosage is your independent variable,

  • the thing that you can change. So, you'll need some coffee. Your result or dependent

  • variable, the thing that depends on the thing that you can change is going to be the speed

  • at which the subject navigates through this giant corn maze.

  • Go out on the street, wrangle up a bunch of different kinds of people and randomly assign

  • them into three different groups. Also at this point, the American Psychological Association

  • suggests that you acquire everyone's informed consent to participate. You don't want to

  • force anyone to be in your experiment, no matter how cool you think it is.

  • So the control group gets a placebo, in this case decaf. Experimental group one gets a

  • low dose of caffeine, which we'll define at a 100 milligrams; just an eye opener, like,

  • a cup of coffee's worth. Experimental group two gets 500 milligrams, more than a quad

  • shot of espresso dunked in a Red Bull. Once you dose everyone, turn them lose in the maze

  • and wait at the other end with a stopwatch.

  • All that's left is to measure your results from the three different groups and compare

  • them to see if there were any conclusive results. If the highly dosed folks got through it twice

  • as fast as the low dose and the placebo groups, then Bernice's hypothesis was correct, and

  • she can rub my face in it saying she was right all along, but really that would just be the

  • warm flush of hindsight bias telling her something she didn't really know until we tested it.

  • Then, because we've used clear language and defined our parameters, other curious minds

  • can easily replicate this experiment, and we can eventually pool all the data together

  • and have something solid to say about what that macchiato was doing to your cognition

  • or at least the speed at which you can run through a maze. Science: probably the best

  • tool that you have for understanding other people.

  • Thanks for watching this episode of Crash Course Psychology; if you paid attention you

  • learned how to apply the scientific method to psychological research through case studies,

  • naturalistic observation, surveys, and interviews and experimentation. You also learned about

  • different kinds of bias in experimentation and how research practices help us avoid them.

  • Thanks especially to our Subbable subscribers, who make this and all of Crash Course possible.

  • If you'd like to contribute to help us keep Crash Course going, and also get awesome perks

  • like an autographed science poster, or even be animated into an upcoming episode, go to

  • Subbable.com/CrashCourse to find out how.

  • Our script was written by Kathleen Yale and edited by Blake de Pastino and myself. Our

  • consultant is Dr. Ranjit Bhagwat. Our director and editor is Nicholas Jenkins, our script

  • supervisor is Michael Aranda, who is also our sound designer, and our graphics team

  • is Thought Café.

Can week-old pizza cause psychedelic hallucinations? Does coffee make you smarter? Or does it just

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    羅紹桀   posted on 2015/07/26
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