Research Statement

During my undergraduate studies, I developed a strong interest in psychology through the exploration of cognitive science literature. This intellectual journey led me to engage deeply with the works of prominent scholars such as Keith Stanovich, Daniel Kahneman, and particularly Gerd Gigerenzer and Herbert A. Simon, whose research on bounded rationality and heuristics left a lasting impression. Subsequently, I became increasingly drawn to mid-level evolutionary theories, including parental investment theory, life history theory, and the antagonistic pleiotropy hypothesis.

At the beginning of my Ph.D. training, I immersed myself in Bayesian statistics. I was intrigued by the realization that Bayesianism is not merely a statistical style but emerges as a logical necessity under specific assumptions, such as those articulated in De Finetti’s representation theorem. I pursued self-directed learning in this area and became particularly fascinated by hierarchical Bayesian models (HBMs), nonparametric models such as Dirichlet process mixture models, and their combinations. The elegant properties of HBMs prompted me to explore their potential for deriving normative models of human cognition and behavior. This led me to engage extensively with the work of John Anderson, Tom Griffiths, Josh Tenenbaum, and their collaborators, and to shift my research focus toward the development of normative models.

My primary research interests lie at the intersection of judgment and decision-making, social cognition, and computational modeling. In the domain of normative modeling, I draw on insights from behavioral economics and evolutionary psychology to investigate how organisms optimize utility functions across different environmental contexts. My first normative model of intertemporal decision-making was published in the Proceedings of the Annual Meeting of the Cognitive Science Society (Oral presentation, 13.8%). In my work on social cognition, I rely heavily on Bayesian inference to build computational models. I am currently developing a theoretical framework for understanding impression formation and maintenance from a computational perspective.

A second strand of my research is grounded in evolutionary biology, with a particular focus on behavioral genetics and genoeconomics. I am interested in how genetic and environmental factors jointly shape the development of complex human behaviors and how these influences manifest in economic outcomes.

The third line of inquiry concerns cultural evolution, geographical context, and agent-based modeling. I investigate the dynamic interplay between cultural transmission and ecological variables in shaping social learning, employing agent-based simulations as a key methodological tool. In my current project, I integrate geometrical and census data to develop an agent-based model populated with Bayesian reasoners, aiming to explain regional variations in stereotype formation.

Education

University of California San Diego, U.S. (2023.9 - )

Ph.D. in Experimental Psychology

Advisor: Prof. Chujun Lin

The Chinese University of Hong Kong, Shenzhen, China (2018.9 - 2020.7)

M.S. in Applied Psychology, GPA: 3.864 (rank: 1/27)

Advisor: Prof. Xiaotian Wang

Highlights:

• Outstanding Graduate 2020
• Academic Excellence Award 2020
• Academic Scholarship Gold Award 2019

Northeastern University, China (2014.10 - 2018.6)

B.S. in Metallurgy, GPA: 3.511 (rank: 36/255)

Advisor: Prof. Xiangning Meng, Prof. Zhuokun Cao

Highlights:

• Postgraduate Recommendation
• Published two mathematical modeling patents; one was sold at a price of 150,000RMB
• Academic Scholarship Award (Class C) 2015, 2016, 2017

Work Experience (2019-2023)

Project Associate: Department of Applied Social Sciences, The Hong Kong Polytechnic University (2022.8-)

Advisor: Prof. Yin Wu

• Generate an experimental program that could provide feedback to participants and repeat trials with no responses. Blended chemical reagents to prepare the olfactory stimuli consisted of androstadienone and propylene glycol. Administered hormones to participants and fitted Bayesian drift-diffusion models using choice and response time data
• Modeled the generative process of self-esteem using reinforcement-learning model, kernel regression, and Gaussian process model under the hierarchical Bayesian framework

Visiting Student: Affiliated Mental Health Center, Zhejiang University School of Medicine (2021.7-2021.9)

Advisor: Prof. Tao Li

• Predicted suicidal behavior in adolescents using interpretable machine learning (e.g., XGBoost)
• Calculated Shapley values of suicide-associated factors and revealed the impact of risk factors on individual predictions
• Estimated a mixed graphical model to examine the developmental trajectory of suicidal behavior

Research Assistant: The Chinese University of Hong Kong, Shenzhen (2020.7 - 2021.8)

Advisor: Prof. Xiaotian Wang

• Build a team workflow using a set of tools like zotero, slack, trello, and git/Github
• Prepare manuscripts, analyze data, and conduct behavioral experiments

Visiting Graduate of Shenzhen Research Institute of Big Data (SRIBD), (2019.3 - 2020.5, 2020.7)

Advisor: Dr. Jianjun Zhou, Prof. Xiaotian Wang, Prof. Kun Zhang (CMU)

• Designed and conducted computer-based experiments
• Analyzed scores on the Internet Gaming Disorder Scale through Item Response Theory to obtain the typical disorder symptoms of CUHK(SZ) students
• Using machine learning and causal inference algorithms (e.g., PC, FCI, and LiNGAM) to recover the antecedents and ramifications of gaming disorder and self-control

Research Projects

Publications

§ Co-first authorship. * Corresponding author.

Long, J.§, Lu, J.§, Hu, Y., Tobler, P. N., & Wu, Y. (2025). Testosterone administration increases the computational impact of social evaluation on the updating of state self-esteem. Biological Psychiatry: Cognitive Neuroscience and Neuroimaging. (in press)

Lu, J., Ye, Y., Wu, Y.* (2024) Little Evidence that Androstadienone Affect Social Distance-Dependent Prosocial Behavior: A Pre-Registered Study Royal Society Open Science, 11, 240004.

Lu, J.§, Jin, Y.§, Liang, S., & Li, T.* (2024) Screening and Explaining Suicide-Associated Factors in Adolescents Using Interpretable Machine Learning and Network Analysis: a Cross-Sectional Study BMC public health, 24.

Samore, T., Fessler, D. M., Sparks, A. M., Holbrook, C., Aaroe, L., Baeza, C. G., … & Wang, X. T. (2024). Accordance and conflict between religious and scientific precautions against COVID-19 in 27 societies. Religion, Brain & Behavior, 1-20.

Lu, J., Yao, J., Zhou, Z., & Wang, X.T.* (2023) Age Effects on Delay Discounting across the Lifespan: A Meta-Analytical Approach to Theory Comparison and Model Development. Psychological Bulletin, 149(7-8), 447–486.

Wang, X.T.*, Wang, P.*, Lu, J., Zhou, J., Li, G., & Garelik, S. (2022) Episodic Future Thinking and Anticipatory Emotions: Effects on Delay Discounting and Preventive Behaviors During COVID-19. Applied Psychology: Health and Well-Being, 14(3), 842-861.

Lu, J.*, Lu, Q.*, & Lu, L. (2022) Differential Effects of Fundamental and Longitudinal Life-History Trade-Offs on Delay Discounting: An Evolutionary Framework. Behavioral Sciences, 12(3), 63.

Samore, T. *, Fessler, D. M., Sparks, A. M., Holbrook, C., Aaroe, L., Baeza, C. G., … & Wang, X. T. (2022) Greater Traditionalism Predicts COVID-19 Precautionary Behaviors Across 27 Societies Scientific Reports, 13(1), 4969.

Manuscript Under Preparation

Lu, J.* & Wang, X.T. (2025). A Normative Model of Delay Discounting Across the Lifespan: Tradeoffs Between Mortality, Fertility, and Parenting. (under revision)

Lu, J., & Lin, C. (2024). From latent constructs to networks: modeling high-dimensional social inferences in naturalistic settings. (under revision)

Skills & Hobbies

Software Operation : R (base & tidyverse), Stan, Python, NetLogo, PsychoPy, Mplus, Citespace, HTML, CSS, Javascript

Language: Chinese, English

Hobbies: Reading & Writing, Chinese Martial Art (under the supervision of the 4th inheritor of Xingyiquan 形意拳), Painting (National Second Prize), Table Tennis

My Story

As an engineering undergraduate, I stumbled upon the talent show The Brain, which allowed people to display their exceptional brain power, including the ability to memorize a shuffled pack of 52 cards in 20 seconds. Dr. Kunlin Wei, a psychology professor at Peking University, served as a scientific judge on the show and introduced fundamental concepts underlying these prodigious feats, such as working memory and mental representation. This experience made a lasting impression on me about what psychology is and how interesting it can be.

Although I gleaned lessons from The Brain, my curiosity about these mental skills did not lead to a passion for delving deeper into psychology. As a pragmatic engineering student striving for academic excellence, I was more captivated by the practical insights psychology offers into improving reading and memory performance. Hoping to utilize psychology to guide my daily work, I regarded myself as sitting at the top of the chain of command over my behavior. However, I was later surprised to find that humans are not entirely in control of their behavior. The metaphor proposed by Richard Dawkins haunted me—humans are vehicles of their genes, and human behavior reflects psychological predispositions that benefit their replication. This raised a crisis of autonomy for me because I could not find any rational justification for life if we were puppets of replicators. I arrived at the belief that the only way to initiate a rebellion against replicators and find meaning in the age of Darwin is to understand ourselves and the surrounding world. Only by answering the eternal questions of who we are and how environments shape human psychology will we discover the meaning of our existence.

Games Primates Play by Dario Maestripieri:

Mitchell was on a quest to understand himself and the world around him. As a scholar, he used scientific and logical reasoning to examine and evaluate theories and discoveries produced by biologists, psychologists, historians, philosophers, and other researchers. His inquiry led him to conclude that evolutionary biology provides the most direct answers to questions about the self and human nature. In his book, he argued that many of our emotions, feelings, and thoughts reflect biological predispositions that help us survive and reproduce. He also wrote that many patterns in human history can be understood as the outcome of nepotistic cooperation among members of one’s own family or group and competition against members of other groups, and that similar social dynamics occur in other primates as well. When discussing the controversies that followed the publication in 1975 of Edward O. Wilson’s book Sociobiology: The New Synthesis, Mitchell bluntly stated: “The problem is not that sociobiology does not make sense. The problem is that sociobiology makes too much sense.”

Satisfied with the way his scientific reasoning produced the knowledge and explanations he was looking for, Mitchell tried to use the same approach to search for a justification of knowledge-seeking in itself and, ultimately, of his own existence. He wanted to be objective at all costs and eliminate all sources of bias that might cloud his analysis, especially the psychological predispositions toward self-interest, survival and reproduction, and life in general. But after searching for and eliminating all of these subjective biases, he couldn’t find any rational justification for knowledge or life. So Mitchell concluded that, taken to its extreme, striving for objectivity ultimately leads to nihilism and rational self-destruction. In his own words: “Life is a prejudice that happens to be talented at perpetuating or replicating itself. To attempt to eliminate this source of bias is to open your mind to death. I cannot fully reconcile my understanding of the world with my existence in it. There is a conflict between the value of objectivity and the facts of my life.”