The origins of social categorization


We’re presenting a short series of abstracts of the work-in-progress our scholars presented and discussed at their June 2017 Working Group Meeting.

Katherine Kinzler is Associate Professor of Psychology and Associate Professor of Human Development at Cornell University,


Forming conceptually rich social categories helps people navigate the complex social world by allowing them to reason about others’ likely thoughts, beliefs, actions, and interactions as guided by group membership. Yet, social categorization often has nefarious consequences. We suggest that the foundation of the human ability to form useful social categories is in place in infancy: social categories guide infants’ inferences about peoples’ shared characteristics and social relationships. We also suggest that the ability to form abstract social categories may be separable from the eventual negative downstream consequences of social categorization, including prejudice, discrimination and stereotyping. Whereas a tendency to form inductively rich social categories appears early in ontogeny, prejudice based on each particular category dimension may not be inevitable.

Keywords: essentialism, infant, intergroup cognition, prejudice, social categorization, stereotype

Can cognitive effort be measured?

Elegant . Mixed media

My central research question for our December 2016 Working Group Meeting is, Can cognitive effort be measured?

There is growing evidence that fluctuations in brain activity may exhibit scale-free (“fractal”) dynamics. Scale-free signals follow a spectral-power curve of the form P(f ) ∝ f−β, where spectral power decreases in a power-law fashion with increasing frequency. In this study, we demonstrated that fractal scaling of BOLD fMRI signal is consistently suppressed for different sources of cognitive effort. Decreases in the Hurst exponent (H), which quantifies scale-free signal, was related to three different sources of cognitive effort/task engagement: 1) task difficulty, 2) task novelty, and 3) aging effects.

These results were consistently observed across multiple datasets and task paradigms. We also demonstrated that estimates of H are robust across a range of time-window sizes. H was also compared to alternative metrics of BOLD variability (SDBOLD) and global connectivity (Gconn), with effort-related decreases in H producing similar decreases in SDBOLD and Gconn.

These results indicate a potential global brain phenomenon that unites research from different fields and indicates that fractal scaling may be a highly sensitive metric for indexing cognitive effort/task engagement.

Marc G. Berman is an Assistant Professor in the Department of Psychology and is involved in the Cognition, Social and Integrative Neuroscience programs, and a Scholar with Virtue, Happiness, and the Meaning of Life.