Everyday Research Methods

Do TikTok dance videos influence body perceptions?

Seeing different size models on TikTok videos affected people's body esteem.
Photo: AlessandroBiascioli/Shutterstock

Have you ever watched dance challenge videos on TikTok? If so, you probably noticed the skill and appearance of the dance model.  Some psychologists have started to study how TikTok dance models affect viewers.  A set of three studies asked, can the size of the dancer on TikTok influence the body satisfaction of a viewer?  Journalists at PsyPost wrote up a summary of this empirical work. The research was originally published in the journal, Computers in Human Behavior; may be paywalled. 

The theory behind the study is related to the potential of social media to impact body esteem:

Media, especially its portrayal of the “thin ideal,” where extremely slim bodies are considered attractive, has a significant impact on shaping these negative body perceptions. With the rise of social media platforms like TikTok, researchers are curious about how this new form of media might influence people’s body image.

Here's a description of the first study. As you read this description, try to identify the variables in the study:

...the researchers recruited 262 women aged between 18 and 25 years for an online experiment.  The participants were randomly assigned to watch TikTok videos featuring thin dancers, large dancers, or videos of animals (the control condition). [Both before and after] watching the videos, participants rated their weight satisfaction, overall appearance satisfaction, and body shape satisfaction.

Body satisfaction significantly increased after watching videos featuring large dancers and control videos (videos unrelated to body appearance). However, after watching videos of thin dancers, body satisfaction showed a slight decrease.

a) Use this chart to identify Study 1's variables (Hint: There are one IV and three DVs)

Variable name	What are the variable's possible levels?	Is this manipulated or measured?	Is this an IV or a DV?	For IVs: is it within groups or independent groups?

b) Which kind of experiment is Study 1: Posttest only? Pretest/posttest? Concurrent measures? Repeated measures? How do you know?

c) Sketch a bar graph or line graph of the results they described (select one of the three DVs). Don't forget to plot both pretest and postest data. 

The researchers did Study 2 to replicate Study 1:

Study 2 largely replicated the findings from Study 1. Watching videos featuring large dancers led to increased body satisfaction, while watching videos featuring thin dancers resulted in decreased body satisfaction.

Study 2 also measured the potential mechanism, or mediator, of social comparison (how often someone compares their appearance to those of others.).  Study 2 found: 

A majority of participants in the thin dancer condition engaged in upward comparison (comparing themselves negatively to the dancers), while a majority of participants in the large dancer condition engaged in downward comparison (comparing themselves positively to the dancers).

One potential internal validity threat to both Study 1 and Study 2 is that participants were told the study was about body satisfaction. In addition, the pretest-postest nature of the design may have nudged participants to report changes in line with the study's goals.

Study 3 attempted to correct this issue with a posttest-only design, and by telling participants that the study was actually about how engaging different TikTok videos are. 

d) What is the name for this type of internal validity threat? 

e) Why would a posttest-only design help control for this internal validity threat?

Here's the journalist's summary:

In Study 3, the researchers recruited 375 women aged between 18 and 25 years and randomly assigned them to watch either TikTok videos of thin dancers or TikTok videos of large dancers. Participants were told that the study aimed to investigate the engagement of TikTok videos. After watching the videos, the participants completed the same measures of body satisfaction used in the previous studies.

Even after concealing the true purpose of the study, the results consistently indicated that watching videos of thin dancers led to lower body satisfaction compared to videos of large dancers.

f) Reread the summary of Study 3 and identify its variables on the table below:

Variable name	What are the variable's possible levels?	Is this manipulated or measured?	Is this an IV or a DV?	For IVs: is it within groups or independent groups?

g) Graph the results of one of the dependent variables in Study 3. 

h) What do you think of this set of studies? Ask questions about the four aspects of validity.

Specifically, when you address statistical validity, use terms like replication and effect size.
When you address internal validity, think about how the study rules out most internal validity threats.
When you address construct validity, ask a question about the measurement of the dependent variables.
When you address external validity, think about the samples used in these studies.

Here's how the researchers concluded an interview about their studies:

“I would like to add that this study shows that watching TikTok videos is not universally negative and that there are positive and negative effects,” Joiner said. “The findings also raise the possibility that TikTok could change its algorithm and show a wider variety of body types, and this could have a major public health benefits. Body dissatisfaction is major risk factor for eating disorders and eating disorders have the highest mortality rate of all psychiatric diseases due to medical complications or suicide.”

Easing the angst of upsetting news

The study tested two different types of stories to see which might ameliorate the stress of reading about tragic news events. Photo credit: Nomad_Soul/Shutterstock

This post contains descriptions of violence in the news.

Have you ever been saddened or dismayed by a news about a terrible event, such as a natural disaster, mass shooting, or a crime? You're not alone; such stories can make us emotional. One psychology researcher, Kathryn Buchanan, was inspired to study people's reactions to news events by her own experience. She was listening to news about the mass shooting at the Ariana Grande concert in 2017. She felt upset at the news, but she also felt some relief, when she later encountered news about examples of people's kindness in the shooting's aftermath. 

This journalist's account in the Washington Post describes how Dr. Buchanan turned her experience into a research idea:

She began to contemplate whether being exposed to heartwarming content could counteract the known negative impacts of consuming harrowing news stories. Common symptoms include heightened stress, hopelessness, anger, anxiety and depression.

So she started a years-long study in 2017,[...]. [The research team] split 1,800 participants into several groups — each of which were shown news clips or articles about a recent U.K.-based terrorist attack or a similar catastrophic event. Some of the groups were solely exposed to upsetting news, while others were subsequently shown a story about [either] a heroic act or a more lighthearted subject.

Here is a description of some of the results:

The group that was strictly shown unsettling news reported increases in negative emotions and decreases in positive feelings. That group also indicated feeling more pessimism about humanity and society. Meanwhile, participants who were also shown stories of kindness reported feeling less negative emotions, coupled with increases of positive emotion. That group reported a more optimistic view of the world.

Participants used two scales from 1 (meaning very slightly or not at all) to 5 (meaning extremely) to assess the level of negativity and positivity they felt before being exposed to the content, as well as after.

Repeatedly throughout their research, Buchanan and Sandstrom saw that uplifting news can provide an emotional buffer against distressing news. They also found that “there’s something special about kindness in particular,” Buchanan said, noting that while amusing stories (such as swearing parrots or classic jokes) diminished the effects of upsetting news, stories about acts of kindness were even more powerful.

a). See if you can classify the variables in the study. Here's a hint: There were four dependent variables and one independent variable. 

Variable name	What are the variable's possible levels?	Is this manipulated or measured?	Is this an IV or a DV?	For IVs: is it within groups or independent groups?

b) Which kind of experiment is Study 1: Posttest only? Pretest/posttest? Concurrent measures? Repeated measures? How do you know?

c) Look at the description of the results, above, for level of positivity only. Sketch a graph of the results they described. Here's a hint: it's important to find a way to include the pretest and posttest scores on positivity. 

d) Think about the four big validities and apply them to this study. Specifically, ask one question to help you interrogate external, internal, construct, and statistical validity.

I appreciated that, in the news story, the journalist mentioned other studies that also measured people's reactions to negative news in the media. Journalists do not often talk about recent studies in the context of an entire literature, but this one did! You can read examples of conceptual replications of this study in the journalist's story (scroll toward the end).  

The empirical study can be read for free here at PLOS One. 

 

"Want to raise kind, generous kids? Take them to an art museum"

Did the study manipulate exposure to art museums?
Photo: AChubykin/Deposit Photos

On my first read of this headline, I was skeptical. "Probably a correlational study behind this one," I thought. As it turns out we are actually looking at an experiment. However, there's another problem with the journalist's coverage of this study. Read on.

The journalist writes for Inc.com, which  summarizes research for the business world. The headline was "Want to raise kind, generous kids? Take them to an art museum" The original empirical article appeared in Psychological Science. Let's work through it. The introduction starts out:

Everyone wants to raise successful kids, but a big part of being successful is being a kind and generous person. So how can parents give their kids the best while also doing their best to ensure they raise decent, thoughtful little people? 

They introduce the idea that art might make kids more generous: 

You may be wondering what possible connection a day viewing Van Gogh or Picasso could have to raising an empathetic kid. Certainly, museums make children more worldly and cultured, but how do they make them kinder? The link, according to the new study, recently published in Psychological Science, is awe. 

a) Before you read more, make a prediction. Given this introduction, what independent variable do you think the researchers probably manipulated? What variable do you think was measured?

Now let's read the details. There were two studies. In the first one, 

..the research team asked 159 volunteers aged 8 to 13 to watch short movie clips. Some of these clips were neutral, others cheerful, and others awe-inspiring. . 

In the second study, about 350 kids participated. The researchers used one of the same three clips for the awe variable (neutral, joy, and awe), but in this case, the generosity variable was operationalized differently:

The researchers then asked the kids [in Study 1] to determine how many items in a list of foods should be donated to a food drive for needy families. Alternately [in Study 2], the kids were given the option of donating their reward for participating in the study--a ticket to a local art museum--to a refugee family. 

(By the way, the original article reports that "The awe-eliciting clip was from the film Song of the Sea, in which the main character turns into a seal and transforms the city while flying above it.")

Back to the Inc.com story for the results: 

"Children who watched the awe-inspiring video chose to count 50 percent more items for the food drive than children who watched the joy-inspiring clip and more than twice as many items as children who watched the neutral clip. [in Study 2], children in the awe-inspiring condition were also 2 to 3 times more likely to donate their museum tickets than children in the joyful or neutral conditions," reports the Association for Psychological Science blog. 

b) Take a moment to classify the two variables in Study 1:

Variable name	What are the variable's possible levels?	Is this manipulated or measured?	Is this an IV or a DV?	For IVs: is it within groups or independent groups?

c) Which kind of experiment is Study 1: Posttest only? Pretest/posttest? Concurrent measures? Repeated measures? 

d) And now for Study 2:

Variable name	What are the variable's possible levels?	Is this manipulated or measured?	Is this an IV or a DV?	For IVs: is it within groups or independent groups?

e) Which kind of experiment is Study 2: Posttest only? Pretest/posttest? Concurrent measures? Repeated measures? 

Look back at the description of the study. Did either Study 1 or Study 2 manipulate "taking kids to an art museum"? Nope. In fact, Study 1 took place online (kids watched video clips on their own computers). And Study 2 took place in a science museum. Neither of the studies manipulated art museum exposure. Art museum tickets were used in Study 2, but only as a way of operationalizing generosity.

That factual error didn't stop the journalist from asserting:

Parents ... can always go to their local art museum to give their kids a guaranteed dose of awe. 

Guaranteed dose of awe? That conclusion does not really follow from this study!  So here are a couple more questions. 

f) What could be an alternative headline for the Inc.com story--one that is more accurate to what the study actually manipulated?

g) The journalist appears to have generalized from one setting (watching video clips) to another (going to an art museum). Which of the four big validities is the journalist treading on here? 

h) Here's a construct validity question: The two studies operationalized the dependent variable, "generosity" in two different ways. Were each of them a good way to measure this variable? Why or why not? What are the strengths of operationalizing the variable more than one way?

i) Now for a question related to internal validity: The main independent variable was the content of the film clip the children saw. To ensure internal validity, what should the researchers hold constant about the film clips used in the three conditions? 

 

 

 

Multivitamins and memory in older adults

Participants in the study took either a multivitamin or a placebo.
Photo: Sorapop Udomsri/Shutterstock

When you shop in a natural foods or general nutrition store, you might see claims that vitamins can improve your health and cognitive function. Scientists don't always test such claims in randomized trials, so it's best to be skeptical until you read research. But a recent study did test whether taking a multivitamin can improve people's memory. In this blog post, we'll check out how an NPR journalist summarized the study.

Before reading on, think about this: How would you design a study to test this question? What would be your independent and dependent variables? What kind of study would you use--specifically, what type of experiment (Posttest only? Pretest/posttest? Concurrent measures? Repeated measures?)

Here's the journalist's summary of the study:

A team of researchers wanted to assess how a daily multivitamin may influence cognitive aging and memory. They tracked about 3,500 older adults who were enrolled in a randomized controlled trial. One group of participants took a placebo, and another group took a Silver Centrum multivitamin, for three years. The participants also took tests, administered online, to evaluate memory.

At the end of the first year, people taking a multivitamin showed improvements in the ability to recall words. Participants were given lists of words — some related, some not — and asked to remember as many as possible. (List-learning tests assess a person's ability to store and retrieve information.)

People taking the multivitamin were able to recall about a quarter more words, which translates into remembering just a few more words, compared to the placebo group.

a) Make a table of the variables in this study:

Variable name	What are the variable's possible levels?	Is this manipulated or measured?	Is this an IV or a DV?	For IVs: is it within groups or independent groups?

b) This was an experiment. How do you know--what are some key words used in the journalist's description?

c) Which kind of experiment is this? Posttest only? Pretest/posttest? Concurrent measures? Repeated measures? 

d) Sketch a graph of the study's results. Here's a hint: You should put time (or pretest/posttest) on the x-axis). 

Next we'll apply the four big validities to this study. 

Construct validity
e) Ask a question about the construct validity of the dependent variable.  What do you need to know in order to assess construct validity of the DV?

Statistical validity
f) One of the questions to ask is about effect size: How much better was the memory in the multivitamin group?  The NPR report offered two quotes related to effect size.  One is from the study's own authors: "'We estimate that the effect of the multivitamin intervention improved memory performance above placebo by the equivalent of 3.1 years of age-related memory change,' the authors write in their paper"

The other is from an independent researcher, who "says the overall effect found in the study was quite small. 'It seems like a pretty modest difference'" 

Do these two people disagree about the study's effect size? 

g) Another aspect of statistical validity is precision. The sample size of the study is relevant here--why? What effect would a large sample (of over 3,000 participants) have on the confidence interval of the estimate?

h) A third aspect of statistical validity is replication, or what else is known? Here's a relevant quote: "Study author Dr. JoAnn Manson...says this is not the first study to show benefits from multivitamins. She points to a study published last year in Alzheimer's & Dementia that showed participants who took a daily multivitamin performed better, overall, on global cognitive function on tests measuring story recall, verbal fluency, digit ordering, as well as executive function."

External validity
i) What do you need to know to evaluate whether the results of this study can generalize to, say, older adults in North America? (check your answer--you did not talk about sample size, did you?)

Internal validity
j) This study is described as a "double-blind, randomized, placebo-controlled" design. Knowing this, you can rule out many internal validity threats. Briefly explain why the study allows you to rule out:

• Selection effects
• Placebo effects
• Testing threat
• Maturation
• History
• Observer bias

At the end of the article, NPR reported

The study was funded, in part, by the National Institutes of Health and other grants. The vitamins were provided by Pfizer Inc. and Haleon, the makers of Centrum, the brand of multivitamins taken by participants in the study. The study authors say the funders had "no role" in the study design, analysis or interpretation.

Why is this statement important for observer bias? 

 

 

 

 

Do puppies remember their siblings?

The studies found that puppies recognize their mothers and that mothers recognize their offspring, but that siblings may not recognize each other after they've lived apart. Photo credit: cynoclub/Deposit Photos

Not an endorsement, but our dog Fig likes to use Rover.com, and the company sent me this article in their email newsletter. 

It's titled, "Do puppies remember their siblings?" I'm happy to talk about any kind of dog research, so let's dive in!

The article covered a couple of studies that tracked how long puppies would remember their siblings and mothers. Before you read on, consider: How could you measure whether puppies remember these early relationships? You can't ask them, so what behaviors might help you decide?

Here's the Rover description of one of the studies.

One study used scent-based tests to determine whether dogs recognized their mother and siblings two years after leaving the litter by the age of 12 weeks. They found that by the age of 2, dogs could only recognize a sibling they lived with—not any of their other siblings.

But dogs could recognize their mothers after two years of separation, and the mothers also recognized their puppies.

The snippet above doesn't provide a lot of information about how the scent-based tests were conducted. However, by looking at the original empirical article, we can learn more details. Specifically, the researchers placed blankets in the beds of dogs' littermates, mothers, and other unrelated dogs that were matched on sex and age. Then they conducted three studies.

In the first one, they tested mother dogs. The mother dogs were presented at the same time with a cloth from one of their offspring (who they'd not seen for about 2 years) and a cloth from an unrelated dog of the same sex and age. Fourteen out of 18 of the mother dogs spent more time sniffing the cloth from their own offspring.

In the second study, offspring were tested. The researchers presented offspring with a blanket from their own mother and from another female dog of the same age. Nineteen out of 25 offspring spent more time sniffing the cloth from their own mother. 

In the third study, dogs were presented with a blanket from one of their own siblings, whom they had not been with in over 2 years, and a blanket from another dog of the same age and sex. Among the 25 dogs who lived alone, they showed no preference for one blanket over another. Among the 23 who dogs lived with one of their siblings (they'd been adopted together), most showed a preference for the blanket from one of their siblings (not the one they lived with) compared to the control blanket. 

a) Start with the first study (with mothers). Make a table of the variables in this study:

Variable name	What are the variable's possible levels?	Is this manipulated or measured?	Is this an IV or a DV?	For IVs: is it within groups or independent groups?

b) Also with the first study: Which kind of experiment is this? Posttest only? Pretest/posttest? Concurrent measures? Repeated measures? 

c) Now do the with the third study (with siblings). Make a table of the variables in this study:

Variable name	What are the variable's possible levels?	Is this manipulated or measured?	Is this an IV or a DV?	For IVs: is it within groups or independent groups?

d) Also with the third study: Which kind of experiment is this? Posttest only? Pretest/posttest? Concurrent measures? Repeated measures? 

Sketch a graph of the results of the third study. Remember to put the DV on the y-axis. 

Now for another study from this article:

Another, smaller study also supports the importance of scent in recognizing dog and human family members. Eight dogs separated from their mother for varying lengths of time—from several months to several years—still reacted more strongly to her scent than the scent of another female dog.

And here's a study that tested whether dogs could recognize the smell of the humans who raised them as puppies (but whom they no longer lived with):

In the same study, researchers also considered nine dogs reared by humans from birth who were separated from their owners for varying lengths of time—from 11 months to just over three years. After this time, the dogs spent longer reacting to their owner’s scent than the scent of a same-sex human who lived with a dog of the same breed and gender.

e) In the "recognize the humans" study, classify the variables: 

Variable name	What are the variable's possible levels?	Is this manipulated or measured?	Is this an IV or a DV?	For IVs: is it within groups or independent groups?

f) Also with the first study: Which kind of experiment is this? Posttest only? Pretest/posttest? Concurrent measures? Repeated measures? 

g) You might have noticed that all of these studies used the same design (did you get concurrent measures?). Why? Could you design an independent-groups version of one of these studies? What might be the advantages and disadvantages of that choice? 

In U.S. football, Whiter-looking men more likely to be head coaches

Football coaching seems to have a stereotype problem
Photo credit: dotshock/Shutterstock

Here's a story from the website Psypost. The headline reads, "Study of U.S. football coaches finds the more White you look, the more likely you are to be head coach".

This report is a study based on a well-known disparity in U.S. football (both college and pro): Even though 57% of college players are Black, Whites are more likely to be in football coach positions. Among college teams, for example, position coaches are around 31% Black; only 9% of head coaches are Black. The higher you look in the coaching leadership hierarchy, the more likely you are to see White men (no women are head coaches of college teams). 

A research team got together to document this disparity and also to study whether men who looked especially "White" were even more likely to be head coaches. In their study, the research team obtained coaches' photos and titles from team publicity programs; all coaches were in the college Football Bowl Subdivision (FBS). Over 100 Black and White coaches were in the sample. In addition to recording the coaches' roles (such as position coach, defensive or offensive coordinator, or head coach) the team also coded how "stereotypically White" or "stereotypically Black" each coach appeared. "Stereotypicality" was coded by showing the photographs to a new sample of Americans, who were asked to rate each coach on a 5-point scale according to how stereotypically White (or, if they were Black, how stereotypically Black) they looked. 

Here's one of the researchers, Melissa J. Williams, explaining to the Psypost journalist some of the background for the study:

“Race and ethnicity have both internal aspects (such as the importance a person places on their cultural heritage) and external aspects (such as how other people perceive a person’s physical appearance). Each of these aspects has a different effect on the role that race plays in a person’s life.  In terms of the specific setting we explored in this paper, football leadership represents an interesting collision of historical stereotypes about Black and White individuals. Black individuals, especially Black men, are stereotyped as good at sports and as physically imposing – characteristics that go with being good at football. Whereas White individuals, especially White men, are stereotyped as confident and charismatic – characteristics that go with being good at leadership. That combination of stereotypes got us interested in looking at who makes it to the top in football coaching, and how their appearance plays into their success.”

Here's how the journalist summarized the study's results:

The findings revealed that White coaches were more likely than Black coaches to occupy leadership roles. Moreover, among White coaches, the more stereotypically White their appearance, the greater the likelihood they occupied a leadership role. When it came to specific roles, appearing stereotypically White increased the likelihood of being a head coach among White coaches. By contrast, appearing stereotypically Black decreased the likelihood of being a head coach among Black coaches.

a) This was a correlational study. What were the measured variables? (There are three variables mentioned in the paragraph above).

b) This result presents a moderator. One way to draw it is to create two matching scatterplots: One for White coaches and one for Black coaches. What would go on the x and y axes of the two scatterplots? What would the slope of each scatterplot be?

c) Write a moderator sentence of this form: _________ moderates the relationship between ________ and __________, such that ________________.

After documenting the correlation between appearing White and being a head coach, the team conducted a second study, an experiment: 

In a second study, Williams and team had a sample of 375 football fans view photos of real college football players. Through a series of trials, participants were shown side-by-side images of two football coaches [both White or both Black], with one being high and the other low in racial stereotypicality. Participants were asked to select which coach they felt would be promoted to head coach in the future.

The results revealed that when the two players were White, participants chose the more stereotypical photo as more likely to become head coach in 70% of trials. But when the two players were Black, participants chose the more stereotypical photo only 52% of the time.Thus, stereotypicality had a stronger effect on being perceived as a leader for White compared to Black football players.

c) What are the independent variables in this experiment? What is the dependent variable?

d) To study the "stereotypicality" variable, this second study used a concurrent measures design. Can you explain why?

e) The first study was correlational and the second was experimental. Why is it helpful to have one of each study type in this investigation? 

At the end of the Psypost article, the researchers were quoted about their study: 

Overall, the researchers said their findings, “provide insight into the insidious nature of racial stereotypes, the role of physical appearance in perpetuating them, and how leadership attainment may be constrained for those who do not look the part.”

Here's a link to the empirical journal article, which includes photos of coaches who were coded as higher or lower on the stereotypicality scale: Personality and Social Psychology Bulletin. 

 

 

 

 

 

 

Stress and food: experimental and quasi-experimental evidence

In one study, department store workers ate more unhealthy foods
when they were working more demanding shifts. Is such a study likely to be
an experiment, a quasi-experiment, or a correlational study?
Credit: 22January/Shutterstock

A Washington Post journalist integrated several health psychology studies in an article about the relationships between stress and eating. For many people, stress and anxiety is associated with weight gain. The journalist summarized several examples of studies that support, and help explain, this link. Read them and think about whether they are  experimental or quasi-experimental. 

Here's the first study the journalist described (we'll call it Study A):

In laboratory studies, scientists have found that administering synthetic versions of cortisol to people causes them to eat substantially more calories than people who are given a placebo. That’s in part because cortisol reduces your brain’s sensitivity to leptin, also known as the satiety hormone, which regulates your appetite and makes you feel full.

a) There are two variables in this study. What are they? What are their levels? For each variable, decide if it is measured or manipulated. 

b) Do you think this was an experiment or a quasi-experiment? Explain your reasoning.

Here's the next one, which we'll call Study B:

In one study of department store workers, people ate more sugar, saturated fat and overall calories when they had to work long, demanding shifts compared with when they worked less stressful shifts with lighter workloads.

c) There are two variables in this study. What are they? What are their levels? For each variable, decide if it is measured or manipulated. 

d) Do you think this was an experiment or a quasi-experiment? Explain your reasoning.

Here's another, which we'll call Study C:

Even stress from activities we enjoy can lead to overeating. In one study, researchers followed ardent football fans in different cities. They found that fans whose NFL teams lost on Sunday consumed more calories and saturated fat the next day. Fans whose teams won ate less food and saturated fat the following day. The scientists found similar results when they looked at the dietary patterns of French soccer fans.

e) There are two variables in this study. What are they? What are their levels? For each variable, decide if it is measured or manipulated. 

f) Do you think this was an experiment or a quasi-experiment? Explain your reasoning.

So far, the evidence suggests that stress in one's life might lead people to eat more of types of foods that are not good for us. Here's a final study that was designed to test a way to prevent stress from affacting our eating habits. We'll call it Study D:

In a study published last year, [researcher Janet] Tomiyama and her colleagues recruited 100 adults with elevated stress levels and split them into two groups. Everyone was trained to do a daily, six-minute stress reduction exercise called progressive muscle relaxation, which involves tensing and relaxing your muscles from toes to head. You can find an example of it here. This deep relaxation technique has been shown in studies to reduce stress and anxiety.

But members of one group were assigned to eat a serving of fresh fruit such as sliced pineapple, honeydew and pears, about five minutes into each of their daily progressive muscle relaxation sessions. After one week of this, the researchers found that eating just the fruit alone made the participants feel less stressed and put them in a better mood. By pairing the fruit with a relaxation exercise, their brains began to view the fruit as something that reduced their stress levels — essentially turning the fruit into comfort food.

g) There are two variables in this study. What are they? What are their levels? For each variable, decide if it is measured or manipulated. 

h) Do you think this was an experiment or a quasi-experiment? Explain your reasoning.

i) Bonus question: Study D included an element of classical conditioning, which you probably learned about in Introductory Psychology. Can you identify the conditioned stimulus and conditioned response in this example? 

j) Rank the four studies (A, B, C, and D, above) in terms of which ones you believe have the strongest evidence (based on their methodology).

Can a cuddly object or blanket reduce adult anxiety?

Does holding a comfort object actually reduce anxiety in adults? That's an empirical question!  Photo: NDanko/Shutterstock

Apparently, about half of American adults still have a childhood teddy bear, and 40% still sleep with it (we can look into the methodology of this survey in a later post!). Do such comfort objects provide anything beyond sentimental feelings?  What about the products marketed to help calm people or help them feel less lonely--products like weighted blankets, or the robotic, stuffed PARO seal, which was created to engage older adults with dementia? 

Time magazine journalist Jamie Friedlander Serrrano covered a variety of studies on these types of comfort objects. The story described several studies that have experimentally tested the effects of weighted blankets, teddy bears, and the PARO seal. One study featured by the journalist was published in the empirical journal, PLOS One. This study focused on a robotic cushion that was plush and soft, and which also mimicked breathing by inflating and deflating every few seconds.

The journalist explained that the researchers wanted to see if holding this object would help students feel less anxious before a stressful oral math exam. 

Students in the test group held the object—a plush, baby-blue cushion the size of a throw pillow that automatically inflates and deflates, mimicking inhaling and exhaling—for eight minutes before their exam. One control group did a guided breathing meditation instead, while another control group didn’t do anything special. Haynes and her team found that clutching the stuffed breathing cushion reduced anxiety as much as doing the guided meditation.

“This indicated that the cushion could be similarly effective as a breathing meditation for anxiety,” says [scientist] Haynes, who is now completing her postdoctoral fellowship at Saarland University in Germany. “We didn’t give the students in the experiment any guidance about using the cushion. We didn’t tell them to follow it with their breathing or anything—it was just purely the act of holding it as it slowly breathed that eased their anxiety. I think we thought it would help with anxiety, but we were pleasantly surprised that it was as effective as the breathing meditation.”

Lywood—who is currently working on commercializing the breathing cushion through her company Sooothe—believes the findings highlight our innate need for touch, even if the source isn’t human or alive, for that matter. “We take touch for granted,” she says. But because many people have been deprived of it during the pandemic, she points out, “we are sort of rediscovering how valuable it is.”

Questions

1. Using the table below, classify the two main variables mentioned in this study (hint: One variable was manipulated and one was measured)

Variable name (conceptual variable)	How was this variable operationalized?	What are this variable's levels?	Was this a manipulated or measured variable?	Was this an IV or a DV?

2. Was the independent variable manipulated as independent groups or within-groups? 

3. Which of the four basic experimental designs was used: posttest only? pretest-posttest? repeated measures? concurrent measures?  Explain your answer. 

4. Sketch a little bar graph of the results of the anxiety result.

5. The journalist doesn't specify whether people were randomly assigned to the three conditions, and when you check the PLOS One article, it also doesn't mention that people were randomly assigned. I don't think we should assume that researchers did NOT take this step--sometimes they just forget to mention it. In any case, why would you need to randomly assign people to the three conditions? That is, what kinds of alternative explanations does random assignment help rule out?

6. One of the authors of the study also created, and hopes to market, the "breathing" cushion. Is this an ethical problem for the study? Is this a scientific problem for the study? 

"Fetuses smile for carrots but grimace over kale"

This fetus's facial expression would be judged as more of a cry or grimace. Photo courtesy of FETAP (Fetal Taste Preferences) Study, Fetal and Neonatal Research Lab, Durham University

This fetus's facial expression would be judged as smiling (or lip-pulling). Photo courtesy of FETAP (Fetal Taste Preferences) Study, Fetal and Neonatal Research Lab, Durham University

Even though kale is having a moment as a vegetable (and kale salad is certainly one of my favorites), most folks would agree that carrots taste better than kale.  A new study, covered by multiple news outlets, has demonstrated that even in utero, fetuses agree. They seem to be able to tell the difference between carrots and kale, and they like carrots better!

As you can imagine, this study was a media darling. Here are some excerpts of a report on this study as covered by journalists at CNN. 

The scientists used in-utero facial expressions to infer how babies felt about what their parent had eaten: 

Fetuses create more of a “laughter-face” in the womb when exposed to the flavor of carrots consumed by their mother and create more of a “cry-face” response when exposed to kale [...]

The study looked at the healthy fetuses of 100 women between the ages of 18 and 40 years who were between 32 and 36 weeks pregnant in northeast England.

From this, 35 women were [assigned at random] into an experimental group that consumed an organic kale capsule, 35 were put into a group that took a carrot capsule, and 30 were put into a control group that was not exposed to either flavor.

After a waiting period of 20 minutes post-consumption, the women underwent 4D ultrasound scans, which were compared to 2D images of the fetuses.

Lip corner pulling, suggestive of a smile or laughter, was significantly higher in the carrot group compared to the kale and control group. Whereas ... casting down of the lower lip...– suggestive of a crying face – [was] much more common in the kale group than the other groups.

Questions

1. Using the table below, classify the three main variables mentioned in this study (hint: One variable was manipulated and two were measured)

Variable name (conceptual variable)	How was this variable operationalized?	What are this variable's levels?	Was this a manipulated or measured variable?	Was this an IV or a DV?

2. Was the independent variable manipulated as independent groups or within-groups? 

3. Which of the four basic experimental designs was used: posttest only? pretest-posttest? repeated measures? concurrent measures?  Explain your answer. 

4. Sketch a little bar graph of the results of the "lip pulling" result.

5. Can this study support the causal claim that "eating a carrot pill causes fetuses to make a smiling face"? Apply the three causal criteria. 

6.  The CNN study mentioned the following in their reporting. Which of the four big validities is this addressing? 

Participants were asked not to consume any food or flavored drinks one hour before their scans. The mothers also did not eat or drink anything containing carrot or kale on the day of their scans to make sure it would not influence the results.

7. The 100 fetuses in this study were not a random sample of any population--they were a convenience sample. Why do you think these researchers did not prioritize external validity in this study? Do you think that's a major problem, or not? 

8. Use the Internet to find other media coverage of this study--note any similarities and differences in how the journalists discuss the findings. 

Here's a link to the original empirical article (paywalled). 

Time alone with your thoughts?

Credit: Ground Picture/Shutterstock

Imagine sitting alone with your thoughts for 20 minutes. You wouldn't be allowed to distract yourself with a book, phone, or even walking around. How much do you think you would you enjoy it?  

When this question was asked of participants in a series of studies, most reported that they'd not enjoy time alone very much.  But this study also tested how well their predictions matched their actual experience. The empirical research was published in the Journal of Experimental Psychology: General, and  summarized in a trade magazine for the American Psychological Association. According to the journalist, 

...study lead author Aya Hatano, PhD, of Kyoto University in Japan[, said] “Our research suggests that individuals have difficulty appreciating just how engaging thinking can be. That could explain why people prefer keeping themselves busy with devices and other distractions, rather than taking a moment for reflection and imagination in daily life.”

The research team conducted six studies. Here is an overview of some of them: 

In a series of six experiments with a total of 259 participants, the researchers compared people’s predictions of how much they would enjoy simply sitting and thinking with their actual experience of doing so. In the first experiment, they asked people to predict how much they would enjoy sitting alone with their thoughts for 20 minutes, without being allowed to do anything distracting such as reading, walking around or looking at a smartphone. Afterward, participants reported how much they had enjoyed it.

The researchers found that people enjoyed spending time with their thoughts significantly more than they had predicted. This held true across variations of the experiment in which participants sat in a bare conference room or in a small, dark tented area with no visual stimulation; variations in which the thinking period lasted for three minutes or for 20 minutes; and one variation in which the researchers asked people to report on their enjoyment midway through the task instead of after it was over. In every case, participants enjoyed thinking more than they had expected to.

a) The researchers conducted six different studies. Do these sound like direct replications? Replication-plus-extensions? or Conceptual replications? (you can skip this question if you haven't done Chapter 14 yet)

b) The journalist identifies these as "experiments," so let's assume that each study contains a manipulated variable. Take this study, as described by the journalist:

The researchers found that people enjoyed spending time with their thoughts significantly more than they had predicted [in a variation of] the experiment in which participants sat in a bare conference room or in a small, dark tented area with no visual stimulation. 

In this study, one of the independent variables was "predicted vs. actual".  What is the other main independent variable, or IV? What is the dependent variable, or DV? 

c) Do the same for this study:

variations in which the thinking period lasted for three minutes or for 20 minutes;

In this study, one of the independent variables was "predicted vs. actual". What is the other IV? What is the DV?

d) And for this one: 

In another experiment, the researchers compared one group of participants’ predictions of how much they would enjoy thinking with another group’s predictions of how much they would enjoy checking the news on the internet. Again, the researchers found that people underestimated their enjoyment of thinking. The thinking group expected to enjoy the task significantly less than the news-checking group, but afterward, the two groups reported similar enjoyment levels.

In this study, one of the independent variables was "predicted vs. actual". What is the other IV? What is the DV?

e) Challenge question: For the study above (comparing time alone to looking at news on the internet)  and graph the result. You can compare your graph to Figure 6 in the empirical article (available next to the APA journalist's story, here).

Here's a final caveat about the results. I appreciated this statement because it puts the statistical outcome in concrete and realistic terms: 

It is important to note that participants did not rate thinking as an extremely enjoyable task, but simply as more enjoyable than they thought it would be, according to Murayama. On average, participants’ enjoyment level was around 3 to 4 on a 7-point scale. Future research should delve into which types of thinking are most enjoyable and motivating, according to Murayama. “Not all thinking is intrinsically rewarding, and in fact some people are prone to vicious cycles of negative thinking,” he said.