Triple major ASU alumna uses interdisciplinary skills to research causality

Rachael Kha grew up in a STEM-oriented environment. Both of her parents earned their degrees from Arizona State University, one with a degree in electrical engineering and the other in chemical engineering. They encouraged her to go to college.

She decided to enroll as a chemical engineering major at ASU, as well as an honors student in Barrett, The Honors College. She looked at it as a practical decision.

“I don’t think I was ever really sure about chemical engineering,” Kha said. “I liked chemistry in high school, and both my parents were engineers, so it just kind of made sense.”

Before taking The Human Event, a yearlong honors course that focuses on key social and intellectual currents in the multicultural history of human thought from the earliest written texts to the present, Kha had never considered studying philosophy. But after she finished those courses, she enrolled in a few philosophy classes and decided to add the topic as a second major.

“Looking back, I was definitely interested in philosophy before college,” Kha said. “In high school, I wrote my common application essay about philosophy and religion, and I liked reading philosophical literature. But I just never really thought about formally studying philosophy until later on.”

Kha continued on her double major track for three years, and during her junior year decided to start working on her honors thesis. She chose to write her thesis on a philosophical topic, quantifying philosopher David Lewis’ idea of causation and causal influence.

Lecturer of philosophy Jeffrey Watson was her thesis director. His mentorship helped guide her through the process.

“Rachael is brilliant and she took her ability to think abstractly and analytically about traditional questions in metaphysics about the nature of causation and then applied this to practical, present-day social problems in a way that can make a difference to how we understand and try to solve these problems together,” Watson said.

Kha already had a substantial background in math from her engineering degree, but she struggled with translating the ideas within Lewis’s conception of causality into quantitative measures and looked to economics for inspiration.

“(Economics) studies complex dynamics among individuals and social systems in a quantitative way, and it actually helped a lot more than I expected,” she said. “I ended up really enjoying my economics classes, so I decided to spend my fourth year finishing the degree.

Since Kha finished all her requirements for the chemical engineering degree, during her final year as an undergraduate, she was able to focus on only taking philosophy and economics classes. 

“Finishing three degrees was definitely difficult at times,” Kha said. “I actually never took more than 22 credits per semester; most semesters were at 18 or 21 credits. But I also took a lot of summer courses while either interning or doing research in a lab, which helped me not overwhelm myself during the fall and spring semesters.”

At some points during her last year, she thought about taking a minor in economics or philosophy instead of a bachelor’s degree, especially since she could have left at any time with a degree in chemical engineering. But Kha felt that earning a degree in chemical engineering was a necessity, while studying philosophy and economics was a choice. 

“I wasn’t sure what I was going to do with just an engineering degree, because I still wasn’t really sure if I wanted to be an engineer at all,” Kha said. “So when I’d feel overwhelmed, I’d just remind myself that I chose to be here and that I’m doing it for myself.

“In choosing to study concurrent degrees, I enjoyed the opportunity to explore and make the most of the many resources of higher education, beyond the value of a degree itself, which I didn’t really consider when I first started college.”

Despite feeling overwhelmed at times, Kha graduated in 2021 with her three bachelor’s degrees and moved into a master’s program for chemical engineering at ASU the following semester. 

She decided on completing a thesis for her master’s rather than an applied project, which has given her more time to conduct research and explore opportunities.

“In June, I presented a paper at the 2022 American Control Conference, which was my first out-of-state conference and my first, first-authored paper,” Kha said. “I’ve also gotten to work with a lot of amazing people from different fields and universities, which helped me decide that I want to continue in research after my master’s degree.”

Although her master’s program is in chemical engineering, Kha found herself pulling skills from her other two degrees to help her through the degree. 

“From philosophy, thinking about paradigms has come up quite a few times,” Kha said. “I’m studying behavioral medicine with respect to physical activity and walking. But one part of what makes this research interesting is that we take a ‘small-data’ perspective to study how we can develop models of individuals’ walking behavior to then design interventions that are tailored specifically to them. 

“So a part of our research involves engaging in the discussion of small-data versus big-data paradigms, which is related to how we understand and validate claims of causality broadly, as well as how our assumptions about what causality is, is reflected in our methods to derive knowledge about causal phenomena from data.”

Kha will be wrapping up her master’s degree this summer and will be starting her PhD in social and engineering systems at Massachusetts Institute of Technology this fall.