It’s not every psychology research project that starts with decorating onesies for the participants, but it’s different when the research subjects are 6 to 24 months old.
In preparation for her research project on infant social judgments, senior Mikaela Overton met with her adviser, chairwoman of psychology Kari McArthur, to iron “Baby Scientist” onto the gifts she planned to give the subjects of her experiment.
“We as a department like to support the areas that students really want to research,” McArthur said. “It’s really an interesting idea, looking at the development of the child’s moral compass in its early foundations: Are they set that early in life? It’s an exploration of important questions in child development.”
Overton planned her summer research project, funded by the LAUREATES program, with McArthur, who was inspired by a visit to the “baby lab” at Yale University.
There, researchers Karen Wynn and Paul Bloom explore social and moral development in infants. In a groundbreaking study published in the influential science journal Nature, they set up an experiment to test babies’ social judgment: How early in life can infants recognize when others are helping or hurting each other?
The Yale study found that “preverbal infants assess individuals on the basis of their behavior toward others,” and concluded these assessments may lay the groundwork for moral thought and social evaluation. When researchers set up a scenario where a “helper” assists a “climber” character up a hill and a “hinderer” knocks him back down, the babies consistently chose the helpful one.
Overton said she wanted her project to expand the Yale study.
“I added looking at infants’ heart rates before, during, and after watching the characters on the stage and while they are choosing the character,” Overton said. “Previous research showed that babies’ heart rates accelerate when they reject their environment or are uncomfortable, and their heart rate lowers when they accept their environment.”
Overton reached out to mothers through faculty baby announcements, preschools, churches, and mothers’ groups in her search for babies from 6 to 24 months, and she ended up with 12 infants and their mothers. In the lab, the child would sit on the mother’s lap before the stage as the researchers reenacted the Yale climber-helper-hinderer scenario.
In order to match the shifts in heart rate with the infants’ attention to the show, Overton used an eye-tracking software that was not used in a previous iteration of the experiment at Hillsdale. McArthur controlled the eye-tracking software to see how long babies paid attention, and which characters they paid attention to.
Sophomore Sydney San Juan, a psychology research assistant, said the video software was an expansion on an earlier version of the experiment conducted by Sarah Milback ’17.
“The big difference between the two projects was that Mikaela used looking-time software to see the baby’s response as the experiment is happening,” San Juan said. “It registers how long the baby looks at each shape, so you can tell which shape they prefer.”
San Juan’s role was presenting the two characters within arms’ reach for the babies to choose which one they thought was “good.”
“My part was going out with the two shapes and asking the baby which shape is good or bad,” San Juan said. “I was behind a curtain so I was blind, but I could see Mikaela’s reaction. More often than not, they chose the good one.”
Though San Juan said the general takeaway from the study was positive — that babies want to pick the helper — the sample size and a few fussy baby scientists meant that the study’s results were inconclusive.
“Unfortunately, we did not find anything significant. Some findings were in the direction we anticipated,” Overton said. “With only a sample size of 12, and with some issues with measuring heart rate — it was connected to their chest, so sometime they would rip it off because they didn’t want it on them. So we couldn’t use some of the babies’ data.”
Even though the findings were inconclusive, Overton will still be able to present her research in April at the Midwest Psychological Association’s conference in Chicago, Illinois.
“The most important takeaway is that some aspects of our hypothesis could be found significant, but a lot of the limitations that we found would just need to be adjusted: a larger sample size, and dealing with fussy babies,” Overton said. “If I was able to do it again, I would be able to control for that. And some babies were tired because it was almost their bedtime, so I would pick a consistent time of day.”
McArthur said an undergraduate psychology experiment can be successful without establishing statistical significance.
“Mikaela did a fantastic job with the planning and execution of her research, and she deserves credit for that,” McArthur said. “We as a department never grade on whether they find statistical significance. We grade on the process: Did they execute good science?”
In addition to presenting at the MPA conference, Overton will present her research on campus during Parents’ Weekend at the Science Symposium for science majors’ research.
Overton plans to continue researching child development during and after graduate school, where she plans to work in developmental psychology with a focus on abused children and children with mental health issues. As for this project, Overton said she hopes others will expand on her research just as she did with Milback’s.
“Mikaela has always wanted to work with kids, and she got to do that with a younger group than she’s done before,” McArthur said. “So that’s just one of many benefits to this study, which was a very worthwhile endeavor.”
