What is Correlational Research? Finding Relationships Between Variables
Summary
TLDRThis video explores the common misconception that correlation implies causation, using the example of a 2003 study claiming that eating pizza reduces cancer risk. It highlights the importance of understanding the difference between correlation and causation, cautioning against jumping to conclusions based on superficial links. The video discusses how other factors, like a Mediterranean diet, could be the real reason behind the observed health benefits, and explains the role of third variables in misleading correlations. It also touches on the illusory correlations found in superstitions and the statistical methods used to measure correlations.
Takeaways
- 🍕 The 2003 Italian study suggesting that eating pizza can reduce the risk of certain cancers was widely publicized but does not imply a direct causal relationship.
- 🧠 Correlation does not imply causation, a common misconception where two related variables are incorrectly assumed to have a cause-and-effect link.
- 🌿 The Mediterranean diet, rich in olive oil, fish, grains, fruits, and tomatoes, is more likely the factor contributing to cancer prevention rather than pizza alone.
- 🔍 The third variable problem cautions against assuming a direct link between two variables when an unknown third variable might be the actual cause of the observed relationship.
- 🎮 The example of violent video games and aggressive behavior illustrates the complexity of establishing causation, where other factors like family violence might be the real cause.
- 🍬 Illusory correlations, like the perceived link between eating candy and hyperactivity, are relationships that people believe exist but are not supported by evidence.
- 🏃♂️ Superstitions in sports, such as rituals performed by athletes, are often based on illusory correlations and not actual causation.
- 📊 Correlation coefficients, like Pearson's R, measure the strength and direction of a relationship between two variables, with values ranging from -1.0 to +1.0.
- ➡️ Positive correlations indicate that as one variable increases, the other also increases, while negative correlations suggest an inverse relationship.
- 📈 Scatter plots are used to graphically represent correlations, showing the direction and strength of the relationship through the pattern of data points.
Q & A
What was the claim made by Italian researchers in their 2003 scientific article about pizza?
-The Italian researchers claimed that eating pizza can reduce the risk of certain cancers.
Why did the study's findings about pizza and cancer risk receive widespread attention?
-The study's findings received widespread attention because it was a surprising and counterintuitive claim that a food often considered unhealthy, like pizza, could have health benefits such as reducing cancer risk.
What is the main caution given by other scientists and the authors of the study regarding the link between pizza and cancer risk?
-Other scientists and the authors caution against assuming a causal relationship between pizza consumption and reduced cancer risk, emphasizing that correlation does not imply causation.
What is the Mediterranean diet, and how is it related to the study on pizza and cancer risk?
-The Mediterranean diet is a diet rich in olive oil, fish, grains, fruits, and tomatoes, which is considered healthier and more likely to contribute to fighting cancer than pizza itself. The study's findings might be more related to the Mediterranean diet than to pizza directly.
What is the 'third variable problem' mentioned in the script, and how does it relate to correlations?
-The 'third variable problem' refers to a situation where two variables appear to be linked, but there is actually an unknown or third variable that is the real source of the link. This problem reminds us that correlation does not necessarily mean causation.
Can you provide an example of the 'third variable problem' from the script?
-An example given in the script is the supposed link between playing violent video games and aggressive behavior. The third variable could be exposure to family violence, which is associated with both increased risk for playing violent video games and youth violence.
What is an 'illusory correlation' as discussed in the script?
-An 'illusory correlation' is a perceived relationship between variables that does not actually exist. The script uses the example of athletes believing in superstitions, such as wearing lucky socks to improve performance, even though there is no actual correlation.
Why do psychologists conduct correlational research, and what do they aim to understand?
-Psychologists conduct correlational research to understand the relationship between two variables, specifically to see how well one variable predicts the presence or absence of another variable.
What is a correlation coefficient, and how is it used in psychology research?
-A correlation coefficient is a statistical measure that quantifies the strength and direction of a correlation between two variables. It is represented by Pearson's R, and its value can range from +1.0 to -1.0, with each extreme indicating a perfect correlation.
How are correlations typically graphed in psychological research, and what do the different elements of the graph represent?
-Correlations are typically graphed on scatter plots, where the slope indicates the direction of the correlation, and the scatter of the data points indicates the strength. Each participant or event is represented by a data point, and the closer the points are to the line of best fit, the stronger the correlation.
What is the difference between a positive and a negative correlation, and can you provide examples from the script?
-A positive correlation implies that as the value of one variable increases, the value of the other variable also increases, such as time spent on a treadmill and calories burned. A negative correlation implies that as the value of one variable increases, the value of the other variable decreases, such as alcohol consumption and judgment.
Outlines
🍕 Pizza and Cancer Risk: Debunking Myths
The paragraph discusses a study by Italian researchers in 2003 that suggested eating pizza could reduce the risk of certain cancers. This led to sensational headlines, but the study did not establish a causal relationship. The text emphasizes that correlation does not imply causation, and the actual factor in fighting cancer might be a Mediterranean diet, which includes pizza ingredients like tomatoes. The paragraph also introduces the concept of the third variable problem, where an unknown variable might be the real cause behind the apparent correlation between two variables. Examples include the relationship between violent video games and aggression, and the potential influence of family violence as a third variable. The paragraph concludes by cautioning against illusory correlations, such as the non-existent link between eating candy and hyperactivity.
📊 Understanding Correlation in Psychology
This paragraph delves into the reasons why psychologists conduct correlational research, aiming to understand the relationship and predictive power between two variables. It explains the correlation coefficient, particularly Pearson's R, which measures the strength and direction of a correlation, ranging from -1.0 to 1.0. The paragraph clarifies that a positive correlation indicates a direct relationship where an increase in one variable is associated with an increase in the other, while a negative correlation suggests an inverse relationship. Examples are provided, such as the positive correlation between time spent on a treadmill and calories burned, and the negative correlation between alcohol consumption and judgment. The paragraph also discusses how correlations are visually represented on scatter plots, with the slope indicating the direction and the scatter indicating the strength of the correlation. The text encourages viewers to pause and check their understanding of these concepts before proceeding.
Mindmap
Keywords
💡Correlation
💡Causation
💡Third Variable Problem
💡Illusory Correlation
💡Mediterranean Diet
💡Superstitions
💡Scatter Plot
💡Pearson's R
💡Positive Correlation
💡Negative Correlation
Highlights
Italian researchers in 2003 claimed that eating pizza could reduce the risk of certain cancers.
Pizza, a popular Super Bowl Sunday food, was linked to fighting cancer in sensational headlines.
The study's authors caution against assuming a causal relationship between pizza and reduced cancer risk.
A Mediterranean diet, rich in olive oil, fish, grains, fruits, and tomatoes, is more likely the cause of fighting cancer.
Correlation does not imply causation, a common error in interpreting relationships between variables.
The 'third variable problem' can create an illusion of a link between two variables when a third variable is the actual cause.
Violent video games and aggressive behavior in children may be linked by a third variable, such as exposure to family violence.
Illusory correlations, like between eating candy and hyperactivity, occur when people perceive relationships that do not exist.
Athletes' superstitions often involve rituals believed to correlate with improved performance, despite no actual causation.
Psychologists conduct correlational research to understand how one variable predicts the presence or absence of another.
Correlation coefficients, like Pearson's R, measure the strength and direction of the relationship between variables.
A positive correlation implies that as one variable increases, the other also increases.
A negative correlation indicates that as one variable increases, the other decreases.
Correlations are graphed on scatter plots, where the slope indicates the direction and the scatter indicates the strength of the correlation.
Positive and negative in correlation do not signify good or bad but rather the direction of the relationship.
The strength of a correlation is not about its goodness or badness but about how well one variable predicts another.
Transcripts
in 2003 Italian researchers published a
scientific article claim that eating
pizza can reduce the risk of certain
cancers that's right one of the most
consumed Foods on Super Bowl Sunday
greasy cheesy salty Pizza is linked to
fighting cancer newspaper headlines
online blogs and editorials picked up on
this astonishing study creating
headlines like eating pizza Cuts cancer
risk why Pizza can fight cancer and
pizza reduces cancer risk now you may be
thinking can eating pizza really cut the
risk of cancer is there a causal
relationship between my favorite meat
lovers deep dish and healthy living well
not exactly you see correlation does not
imply causation that is to say if a is
related to B that doesn't necessarily
mean a cause B this is a common error in
our thinking looking deeper into the
research findings there's much more than
meets the
ey in this pyemia episode I explore
correlations how two variables yes even
peace and health are
[Music]
related it is very tempting and even
exciting for food lovers to read these
aformentioned headlines and think that
eating pizza can cause a reduction in
cancer risk but other scientists and
even the authors of the study caution
readers to quickly make a cause your
relationship it turns out that a
Mediterranean diet is more likely the
cause of fighting cancer in Healthy
Living a diet that is rich in olive oil
fish grains fruits and yes tomatoes one
of the main ingredients on a
pizza why does a correlation not imply
causation it is common to think that
when two things relate to one another or
appear linked like money and happiness
violent video games and aggressive
behavior and eating breakfast and
success in school that one caused the
other but but there are several reasons
to be cautious for instance maybe
there's a third variable often times two
variables appear to be linked to each
other but in actuality there is another
unknown or third variable that is a real
source of the link this is called the
third variable problem let's take a look
at one of these examples for decades
psychologists have investigated a link
between first-person killing games like
Grand Theft Auto and Call of Duty and
aggressiveness in boys one could argue
that playing violent video games causes
aggressive behavior this argument
supports why politicians in the past
have tried to put an age limit on
purchasing violent video games however
one could also make the argument that a
child who is already aggressive is more
likely to seek out and play violent
video games because it connects to their
personality of course what about a third
variable some Studies have shown that
exposure to Family Violence like spous
and child abuse is associated with youth
violence and increased risk for playing
violent video games
this finding reminds us that we should
not jump to conclusions when
establishing links between two
variables it is also very common for
people to see relationships between
variables when non-exist like eating
candy and hyperactivity this is called
an illusory
correlation let's take a look at a
common example of ubiquitous in sports
superstitions athletes are renowned for
being
superstitious they often develop unusual
rituals to keep hitting streaks alive or
to end terrible slubs for example
anything to get the bad juju off their
back whether wearing the same lucky
socks or eating the same meal before
every game from a psychological
perspective athletes have convinced
themselves that a relationship exists
between performing specific rituals and
Performing well on a field unfortunately
this relationship is merely a
fallacy so why do psychologists conduct
correlational research foremost
psychologists are interested in the
relationship between two variables
specifically how well one variable
predicts the present presence or absence
of another variable psychologist study
relationships in all walks of life like
the relationship between attendance and
GPA money and happiness intelligence and
income and depression and eating habits
notice how the arrows are pointing in
both directions as I stated previously
this is because it's very difficult to
make a cause a relationship between two
variables figuring out how closely two
variables relate to or predict one
another is measured using a statistical
measure called correlation coefficient
this index measures the strength of a
correlation represented by Pearson's R
the value of a correlation can range
from positive 1.0 to negative 1.0 each
being a perfect correlation an R of Zer
means no relationship exists between two
variables a correlation of positive 87
for example will be considered very
strong while a negative .27 will be
considered weak before we move on check
your understanding of the strength of a
correlation take a look at the following
following our values and identify the
strength of each score pause the video
here how' you do think about the
mistakes you made if any and Rewind the
video to clarify any confusion it is
important to note that positive doesn't
mean good and negative doesn't mean bad
but rather positive and negative signify
the direction of the
correlation specifically a positive
correlation implies that one variable
predicts the presence of another
variable in other words as the value of
one variable increases the value of the
other variable increas Es as well for
example there is a positive correlation
between the time you spend on a
treadmill and the number of calories
burned in other words the more you run
the more calories you lose there's also
a positive correlation between the
amount of coffee you drink and level of
alertness the more coffee you drink the
more alert you will be in the classroom
or office conversely a negative
correlation applies that one variable
predicts the absence of another variable
in other words as the value of one
variable increases the value of the
other variable decreases Ines for
example there is a negative correlation
between alcohol consumption and judgment
in other words the more alcohol you
drink the less judgment one has there's
also a negative correlation between the
amount of garlic in your home and
vampires the more garlic K in your
kitchen the less Vampires will step foot
in your house check your understanding
of positive and negative
correlations pause the video here and
brainstorm a few examples before moving
on lastly how do psychologist graph
correlations correlations are graphed on
Scatter Plots like the one seen above
the slope of the scatter plot indicates
the direction of the correlation while
the scatter of the data points indicates
the strength each participant or event
in a study is represented by a DOT or
data point on the scatter plot the more
scattered between data points for
example would mean there's a weak
correlation between two variables the
closer the data points are bunched
together on the line of best fit would
indicate a stronger relationship
before we finish check your
understanding of the correlational
method fill in the blanks to make the
statement accurate pause the video here
before checking your answers if you had
any trouble filling in the blanks run
the video and continue the
[Music]
review
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