The Markman Lab

Principal Investigator

Ellen M. Markman

email: markman at
phone: 650-725-2427

Ellen M. Markman is the Lewis M. Terman Professor at Stanford. She was elected to the American Academy of Arts and Sciences in 2003 and to the National Academy of Sciences in 2011. She is a recipient of the American Psychological Association’s Division 7 Outstanding Mentoring Award and the American Psychological Society’s William James Lifetime Achievement Award for Basic Research.

Markman’s research interests include the relationship between language and thought; early word learning; categorization and induction; theory of mind and pragmatics; implicit theories and conceptual change.

Ellen is especially interested in working with new students on how theory-based explanations can be effective interventions in health domains. Please see the Gripshover and Markman paper as an example of this approach.

selected publications

Lab members

Eleanor Chestnut, Graduate Student

email: ekc at

Language is a powerful way of transferring knowledge to children. Not only can language be used to explicitly teach, it can also affect perception, beliefs, and conceptual development in many subtle and implicit ways. In my work, I explore the kinds of information adults communicate implicitly to children. Specifically, I am interested in whether language intended to express equivalence may instead backfire and create contrasts between concepts. Upon hearing, "Tangerines are similar to oranges," for example, a child may infer, based on the word order, that oranges are more typical or common than tangerines. This inferential process would arguably be useful in the cognitive domain, as it would allow children to learn about the world from minimal linguistic input. This same process, however, may have unintended consequences in the social domain. Stating that girls can do science as well as boys, for example, may subtly suggest to children that boys are the typical, or better, scientists.

I received a B.A. in Linguistics and Cognitive Science from Pomona College in 2010, and then worked as the Lab Coordinator for David Barner's Language and Development Lab at the University of California San Diego for two years before coming to Stanford.

Kara Weisman, Graduate Student

email: kweisman at

I am interested in children's developing "philosophy of mind" - specifically, how children (and adults) reason about sentience, consciousness, and personhood. How do we know when we're in the presence of a sentient creature? What kinds of capacities or properties do we expect sentient creatures to have, or not to have? Answers to these questions might change over development and are likely to differ across individuals with different cultural and educational experiences, with consequences in both the cognitive and sociomoral domains. Most of my work examines social reasoning through behavioral studies with children and adults, but I have recently become interested in examining cultural products, such as picture books, that serve both as records of adults' ideas about personhood and as sources of input for children as they learn what it means to be a person.

Before coming to Stanford, I worked as a research/editorial assistant for Elizabeth Spelke at Harvard University; as a research assistant in the Center for Teaching and Learning at the University of Virginia; and as the lab manager of Kristin Shutts' Social Kids Lab at the University of Wisconsin-Madison. I received a B.A. in Cognitive Science from Yale University in 2009.

Derek Powell, Post-doctoral Scholar

email: derekpowell at

I’m interested in how people form and think about abstract ideas. This has led me to study a variety of higher-order cognitive processes, from causal learning to moral reasoning. Currently, my interests are focused on how systems of beliefs are formed, how beliefs interact with one another, and how beliefs might be revised in light of new evidence. In a recent study, my collaborators and I found that pro-vaccine messages were more effective if they focused on the dangers of failing to vaccinate rather than the safety of vaccines. We speculate that assurances of safety may fail because they conflict with wider skeptical beliefs about medicine, but that warnings of danger succeed because they are consistent with wider beliefs about the dangers of disease.

Ellen and I are currently investigating how coherent belief systems can be supported by explanation and deeper understanding. We hope to develop educational interventions that change beliefs and support motivation for positive health behaviors like eating well and managing diseases like diabetes.

Before coming to Stanford, I received my PhD in cognitive psychology from the University of California, Los Angeles. My advisor was Keith Holyoak.

Cai Guo, Graduate Student

email: caiguo at

Categorization is one of our indispensable cognitive tools for making sense of the world. However, the biases, such as psychological essentialism, that exist in the processes of categorization can lead to unwanted consequences, especially in the social domain. For example, we often make assumptions about a familiar category that might not apply to the category’s “atypical” members whom we might judge negatively simply because they do not neatly fit our preconceptions about that category. How can we “outsmart” these cognitive biases we are so prone to in conducting categorization? How should we reason about category boundaries and fuzziness? Is it possible to revolutionize the system of concepts, which are mental representations of categories? And what role does language play in the cognitive processes of categorization? These are the questions I am deeply interested in. Recently, I’ve been contemplating upon the relationships between generic language and category normativity, the connections between categories and their properties, and the alternatives to the dichotomous view of certain categories. In the long run, I hope to apply my research to helping the LGBTQ community, especially in regard to people’s attitudes toward gender non-conformity.

Before coming to Stanford, I earned my BA in Psychology from Dickinson College in Carlisle, PA in 2016. During my undergraduate study, I worked as a summer research assistant under Susan Carey in the Harvard Lab for Developmental Studies and under Yarrow Dunham in the Yale Social Cognitive Development Lab.

Current research assistants