By Published: June 4, 2024

In her honors thesis, recent graduate Amber Duffy describes how loneliness influences a person’s ability to respond to stress


Amber Duffy, who graduated last semester magna cum laude, didn’t always plan to write an honor’s thesis.

She came to the University of Colorado Boulder on a pre-med track, studying neuroscience, but an introductory psychology class knocked her off that path and inspired her to change her major.

“I really liked the behavioral aspect of psychology,” she says.

She liked psychology so much, in fact, that she wasn’t content simply to study it. She wanted to contribute to it. “If I’m not going to do medical school anymore,” she remembers thinking, “I should delve into research.”

Amber Duffy

Recent psychology and neuroscience graduate Amber Duffy won the the Outstanding Poster Presentation Talk award at the Society for Personality and Social Psychology’s Annual Convention in San Diego, recognizing her research on loneliness.

She contacted Erik Knight, a CU Boulder assistant professor of psychology and neuroscience, with whom she’d taken a class her sophomore year, and he invited her to join his lab. She ended up working there for two years, during which time she decided to write an honor’s thesis.

The topic? Loneliness and its effect on young adults’ stress responses.

Why loneliness?

Duffy’s interest in loneliness isn’t purely academic. Many of her friends and family have struggled with it for years, even before the pandemic, she says. And she herself, the daughter of a Taiwanese mother and a Pennsylvanian father, has often felt its sting.

“Growing up in a multicultural family in my predominantly white town”—Castle Rock, Colorado—“it was hard for me to connect with people sometimes,” she says. “I would learn about my mom’s culture at home and then go to school or talk with friends, and they just didn’t understand how I lived.”

Her concerns over loneliness only increased when she learned of Surgeon General Dr. Vivek H. Murthy’s that the United States is suffering from a loneliness epidemic.

“The mortality impact of being socially disconnected is similar to that caused by smoking up to 15 cigarettes a day,” Murthy states.

Hearing this spurred Duffy to action. She wanted to contribute to the fight against loneliness and its potentially negative consequences.

“If we expand our knowledge of loneliness,” she says, “maybe there’s a way we can come up with a more substantial treatment.”

More gas, less brakes

For her honors experiment, Duffy gathered 51 CU Boulder undergraduates between the ages of 18 and 34 and divided them randomly into a control condition and an experimental condition. Those in the former provided a low-stress comparison to those in the latter, who were put through the wringer.

First, the subjects in the experimental condition had to interview for a high-stakes job Duffy and Knight had concocted specifically for the study.

“We told them, in the moment, ‘You have five minutes to prepare a five-minute speech on why you’re the perfect applicant,’” says Duffy.

Immediately following that, subjects had to solve subtraction problems for five minutes, out loud, perfectly, starting at 6,233 and going down from there in increments of 13. “If they made a mistake,” says Duffy, “they had to start over.”

While the subjects ran these gauntlets, Duffy monitored their heart-rate variability (HRV), or the change in interval between heartbeats, and their pre-ejection period (PEP), or the time it takes for a heart to prepare to push blood to the rest of the body. Both serve as indicators of how a person’s stress-response system is functioning, Duffy explains.

Finally, when the stress tests were done, the subjects completed the questionnaire, which research has found to be a reliable means of measuring loneliness.

Duffy had hypothesized that lonelier subjects would have more pronounced stress responses than less lonely subjects, and indeed that’s what her data revealed.

Lonelier subjects had higher heartrates, stronger responses from their sympathetic nervous systems (SNS) and weaker responses from their parasympathetic nervous systems (PNS). Duffy likens the SNS, which controls the fight-or-flight response, to a car’s gas pedal and the PNS, which counterbalances the SNS, to a car’s brakes.

When met with stressful situations, then, lonelier individuals had more gas and less brakes, which Duffy says could have long-term health implications.

Yet she is also quick to point out that more research needs to be done, preferably with more subjects.

If we expand our knowledge of loneliness, maybe there’s a way we can come up with a more substantial treatment.”

“We only had 51 people. An increase in sample size would help with more reliable data,” she says. “It’s also important to look at more clinical and diverse populations because there are other factors that could affect loneliness levels.”

Posters, prizes and professorships

Duffy submitted an abstract of her research to The Society for Personality and Social Psychology’s Annual Convention in San Diego, where she hoped to present a poster, thinking this would be a nice, low-key way of getting some conference experience under her belt.

Her abstract was accepted. But then a conference organizer asked her if, in addition to presenting a poster, she could also give a fifteen-minute talk. She would be the only undergraduate at the conference to do so.

Duffy balked. The thought of speaking to a roomful of PhDs intimidated her. “Most of my life I’ve heard how cutthroat academia is,” she says. But she ultimately agreed, and she was glad she did.

Her talk and poster presentation went so well that not only did she receive interest and encouragement from several doctoral programs, but she also won an award that she didn’t even know existed: the Outstanding Poster Presentation Talk award.

“In the middle of my poster presentation, a woman came up to me—I didn’t know who she was—and said, ‘I have a check here for you for $500.’ I didn’t know that was supposed to happen, but it was great!”

Now graduated, Duffy isn’t 100% sure what her next steps will be, but she’s leaning toward one day pursuing a PhD.

“When you get a PhD, you get to do research and also work with students,” she says. “I think it would be fun to be a professor and give back in that way.”


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