Everyday Research Methods

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.

 

 

Where do you get more creative ideas?

The research tested whether people came up with more, and more creative, ideas when working face-to-face compared to Zoom.
Photo credit: MBI/Alamy Stock Photo

Apparently, researchers have found that Zoom can stifle pairs' creativity. Here's how an empirical study on this topic was introduced by journalists writing for The Guardian:

While the benefits of Zoom and other videoconferencing tools made them indispensable in the pandemic, the research suggests that heavy reliance on the technology comes at a cost to creative thinking.

a) Before moving on, how might you design an experiment to test which type of meeting would be better for creativity? What would your study's independent variable (IV) be? What would the dependent variable (DV) be? 

Let's see how the researchers did it. According to the journalist,  

... the researchers recruited more than 600 volunteers who were paired up to tackle a creativity task either together in the same room, or virtually over Zoom.

The pairs had five minutes to come up with creative uses for a Frisbee or bubble wrap and a minute to select their best idea. Independent judges ruled that turning a Frisbee into a plate was less creative than using it to knock fruit from a tree, while using bubble wrap to send morse code messages was more creative than using it to protect a baby. Overall, those who worked over Zoom had 20% fewer ideas than those who met face to face.

b) In the study above, what was the IV and what were its levels?

c) Was the IV manipulated as between groups or within-groups?

d) What was the DV and what were its possible levels?

e) What simple experiment is this: Posttest-only? Pretest-posttest? Repeated measures? Concurrent measures? 

Now here's a second experiment: 

The same effect was apparent in the real world. In a field study, the researchers analysed ideas for new products generated by 1,490 engineers for a multinational company. The engineers, who were in Finland, Hungary, India, Israel and Portugal, were randomly paired up and given an hour or so to brainstorm products either in person or over Webex videoconferencing. They then selected their best idea.

...the researchers report that the engineers produced more ideas, and more innovative ideas, when working face to face. “They are not only generating a larger number of creative ideas, but their best idea is better,” 

f) This experiment was billed as a "field study." What does that mean? 

g) In the study above, what was the IV and what were its levels?

h) Was the IV manipulated as between groups or within-groups?

i) What were the two DVs in this study?

j) What simple experiment is this: Posttest-only? Pretest-posttest? Repeated measures? Concurrent measures? 

k) The second study is a replication of the first one. What role does replication play in the scientific process? If you've studied Chapter 14, you could identify whether this was a direct replication, a replication-plus-extension, or a conceptual replication.

Interestingly, the journalist notes, "it is unclear whether the impact on creativity holds for larger teams." This statement is a good example of external validity as it applies to situations (rather than the most common focus of external validity, which is on a study's generalizability to participants).

l) What other situations might we wonder about as we consider the external validity of this research? 

The original empirical study was published in Nature. The original study contains a number of interesting additional DVs, including potential mediators for the overall effect on creativity. 

Therapy dogs in the emergency room

The study focused on therapy dogs' effect on perceptions of pain in emergency room patients. Photo: monkeybusiness/Deposit Photos

Adults and children alike can benefit from petting a therapy dog (a friendly pet who makes rounds with a trainer, perhaps to a clinic, pediatric unit, or even on campus during finals week). In this study, covered by journalists at NPR news, researchers from the University of Saskatchewan tested the efficacy of therapy dogs for people who visited an emergency room (ER) complaining of pain. 

 

Here is how the journalist described the study: 

In a controlled trial, researchers asked more than 200 patients to report their pain levels. One group of patients received a 10-minute visit from a therapy dog and the other group did not. After the dog visit, researchers asked patients in both groups to report their pain levels again.

Those who spent 10 minutes with the dog reported less pain [over time], the study found.

Based on this simple description, you can assume that this study was an experiment. 

 

a) What was the independent variable (IV)? What were its levels?

b) Was the IV manipulated as independent groups or within groups? 

c) What was the dependent variable (DV)? 

d) Which of the designs in Chapter 10 does this represent: Posttest only? Pretest-posttest? Repeated measures? or Concurrent measures? 

e) Sketch a small graph of the study's outcome. You don't know what the exact values are, but you should be able to estimate what should be higher and lower. Use either a bar graph or a line graph, following examples in Chapter 10. 

 

The journalist states, "A new study shows that a 10-minute visit from a therapy dog can help relieve patients' pain in the emergency room."  

f) What makes this a causal claim?

b) Assuming that people were randomly assigned to the two groups. Can the study support this causal claim? Name and apply the three causal criteria. 

 

You can read the real study for free: The empirical article is open access in PLOS. 

Swapping saliva

According to the study, even babies know that we don't share our food with just anybody... Photo: szefei/Shutterstock

When you see the photo here, you probably assume the kids are siblings, or at least very close friends. It's not the matching dresses--it's because they're taking turns tasting the same ice cream cone--an activity in which they'll undoubtedly exchange saliva. We humans tend to conclude that people willing to share spit with each other are probably more intimately related. 

Do babies realize the same thing? Apparently so! Here's an NPR story about a research study on whether babies also conclude that people who share saliva  also conclude that they are more closely related. They introduce the story like this: 

"From a really young age, without much experience at all with these things, infants are able to understand not only who is connected but how they are connected," says Ashley Thomas of MIT, who studies what babies and young children understand about the complexities of their social world. "They are able to distinguish between different kinds of cooperative relationships."

As is usually the case, researchers have to get creative to study what young kids think. The present set of studies tested both infants (aged 8-10 months) and young toddlers. They used a puppet show to experimentally manipulate different variables: 

One of their videos shows a woman rolling a ball back and forth with a blue fuzzy puppet. Then another woman shares an orange with that same puppet by putting a slice of orange in her mouth, then letting the puppet nibble on the slice, and then putting it back in her own mouth.

Then they used looking time to measure what infants were thinking:

...the video then shows the two women with the blue fuzzy puppet in between them. The puppet starts to cry and puts its head down, as if it is suddenly unhappy.

When the puppet cried, infants and toddlers looked first and looked longer at the woman who had shared bites of her orange.

"They're looking in that direction because they expect something to happen there," says Thomas. "They expect that woman to be the one to respond to the puppet's distress."

Questions:

a) What is the independent variable (IV) in this experiment? What were its levels? Is it manipulated as independent-groups or within groups? 

b) What is the dependent variable (DV)?

c) Which of the four simple experiments does this seem to be--pretest-posttest? posttest only? concurrent measures? or repeated measures?

d) Sketch a bar graph of the results, putting the IV on the x-axis and the DV on the y-axis. 

Here's another part of the study: 

When the two women were shown with a totally new puppet that started to cry, however, infants and young children looked at both women equally often. This suggested that they didn't see this particular food-sharing woman as especially helpful; instead, her relationship with the puppet was what really mattered.

e) Sketch a bar graph of these results, putting the IV on the x-axis and the DV on the y-axis. 

Like most modern research articles, this one includes multiple studies (three studies, in fact). Additional studies help provide replications of the observed effects, and can also help rule out alternative explanations.  Here is the journalist's description of one of the other studies in the empirical journal article:

To make sure it wasn't just sharing of food that seemed to make babies infer the existence of a close social connection, the researchers created another, similar video. This time, instead of sharing an orange slice, a woman simply put her finger in her own mouth and then put it in a purple puppet's mouth, before putting it back in her own mouth.

Then that same woman also interacted with a green puppet, touching its forehead and then touching her own forehead. After that, the video showed the woman seemingly in distress, with the purple and green puppets looking on.

Infants and toddlers gazed at the purple puppet that had the more intimate, finger-in-the-mouth interaction, as if expecting this puppet to be more affected by the woman's consternation, presumably because they seemed to have a closer relationship.

f) What are the IVs and DVs in this new study?

g) Sketch a bar graph of the results being described.

h) What type of replication is this: a direct replication, a conceptual replication, or a replication-plus-extension? 

i) One possible explanation for the infants' looking behavior in this study is that infants just prefer to look at purple puppets more than green puppets. How could the researchers rule out this alternative explanation? 

Want to read more? here's a link to the empirical journal article, which appeared in the journal Science.

Curbing hate speech with empathy

The study found that empathy-inducing responses like this were more likely to be followed by people deleting their original hateful posts. Photo courtesy of the author

Hate speech abounds on certain corners of social media. Some people post racist, sexist, anti-immigrant, or homophobic comments, and these contribute to a harmful and hateful discourse online. Some companies filter, censor, or censure accounts when they cross the line. Other companies have proved unwilling to ban such content, citing free speech concerns. Recently, some researchers asked if people might engage with such posters online in order to prevent them from posting hate speech. 

The website Optimist Daily ran a story about their work. Here's how they introduced it: 

Led by public policy professor Dominik Hangartner, the research team identified 1,350 English-speaking Twitter users who had posted racist or xenophobic content. The researchers then assigned these users randomly to a control group or one of three test groups. The test groups were then prescribed different counterspeech strategies: empathy-eliciting messages, humor, or warning of consequences.

For example, the empathy eliciting messages might have read "your post is very painful for Jewish people to read...", or "For African-Americans, it really hurts to see people use language like this". Another example can be seen in the comment about immigrants in the photo above, accompanying this post.  

The humorous messages included a meme of an animal with a quip such as "please sir, stop tweeting".

The warning-of-consequences messages read, for example, "Hey, remember that your friends and family can see this tweet too." 

What happened after one of these responses was posted? Here is how the journalist described the results: 

The researchers found that by far, the most effective strategy for getting these users to delete or amend hateful content was counterspeech messages that elicit empathy.

Questions

a) What words in the journalist's story convey that this was an experiment?  I would additionally classify it as a field experiment--can you see why?

b) What was the independent variable? What were its levels? Was the IV manipulated as independent-groups or within groups?

c) There are two dependent variables mentioned in the quotes above. What are they? If you were the researcher, what other DVs would you be interested in? (you can consult the original study to see some of the other DVs)

d) How were the participants in this study selected? Did they use a random sampling method? Or something else? 

e) This study was approved by the researchers' IRB, but the participants in this study apparently did not provide informed consent to participate in the research. Why do you think the IRB approved the study?

Here is a link to the original journal article in PNAS. You can use it to study the graphs of the study's outcome.