Clocks on Shelf

Donnelly, Kristin, Giovanni Compiani, and Ellen R. K. Evers, “Time periods feel longer when they span more boundaries: Evidence from the Lab and the Field,” in press at Journal of Marketing Research.

  • Einhorn New Investigator Award

On Time Perception


Seven experiments (total N = 3,585) and a large field dataset (N = 1,820,671) demonstrate that time periods of equal duration are not always perceived as equivalent. We find that periods feel longer when they span more time categories (e.g., hour, month). For example, periods like 1:45pm – 3:15pm and March 31st – April 6th (boundary-expanded) feel longer than, say, 1:15pm – 2:45pm and April 2nd – April 8th (boundary-compressed). Reflecting this, participants anticipated completing more work during boundary-expanded periods than equivalent boundary- compressed periods. This effect appears to result from the salience and placement of time boundaries. As a consequence, participants preferred scheduling pleasant activities for boundary- expanded and unpleasant activities for boundary-compressed periods. Moreover, participants were willing to pay more to avoid—and required more money to endure—a long wait when it was presented as boundary-expanded. Finally, data from over 1.8 million rideshare trips suggest that consumers are more likely to choose independent rides (e.g., UberX) when they are boundary-compressed when the alternative shared option (e.g., UberPool) is boundary-expanded. Together, our studies reveal that time periods feel longer when they span more boundaries, and that this phenomenon shapes consumers’ scheduling and purchasing decisions.

On Repeated Viewing


Reality is fleeting, and any moment can only be experienced once. Re-watching a video, on the other hand, allows people to observe the exact same moment in time repeatedly. We propose that people apply their understanding of repetition in the real world to the replay context, failing to fully distinguish behavior that they merely observe again (through video replay) from that behavior being performed again in the exact same way. Nine experiments (N = 9,580) support this idea across a broad assortment of stimuli that includes auditions, dances, commercials, and public speeches. We demonstrate that re-watching makes a videotaped behavior appear more rehearsed and less spontaneous, as if the actor in the replayed video were simply precisely repeating the same set of actions. We rule out alternate explanations including repetition increasing accuracy of judgments, mere exposure leading to a positivity bias, and experimenter demand effects. These findings build on an influential literature showing that incidental video features like perspective or slow motion can meaningfully change how people judge the action of the video. Video re-watching may inadvertently shape judgments in contexts ranging from mundane to consequential. To understand how a video is going to influence its viewer, one will need to consider not only its content, but also how often it is viewed.


Donnelly, Kristin, William Ryan, and Leif Nelson, “Once and Again: Repeated viewing affect judgments of spontaneity and preparation,” invited revision at Proceedings of the National Academy of Sciences.

Enamel Mugs

Perfecto, Hannah, Kristin Donnelly, and Clayton Critcher (2019), “Volume Estimation through Mental Simulation,” Psychological Science, 30, 80-91.

On Volume Perception


Although mental simulation underlies many day-to-day judgments, we identified a new domain influenced by simulation: volume estimation. Our simulation-informs-perception account proposes that people often estimate a container’s size by simulating filling it. First, this produces an orientation effect: The same container is judged larger when right side up than when upside down because of the greater ease of imagining filling an upright container. Second, we identified a cavern effect: Imagining pouring water through a narrow opening toward a relatively wide base produces a sense that the container is cavernous and large (compared with identically sized, wide-topped, narrow-based containers). By testing for and demonstrating the importance of simulation to these effects, we showed how complex perceptual judgments can be distorted by higher level cognitive influences even when they are necessarily informed by modularly processed perceptual input.

On Position Effects in Eyewitness Identification


As part of a criminal investigation, the police often administer a recognition memory task known as a photo lineup. A typical 6-person photo lineup consists of one suspect (who may or may not be guilty) and five physically similar foils (all known to be innocent). While they originally presented options simultaneously (i.e., all photos shown at once in a grid), approximately 30% of U.S. police departments have moved to using the sequential lineup procedure over the last 30 years. This raises an important question: Does appearing in certain positions make a suspect more or less likely to be identified? The results of two experiments (N = 10,449) found that eyewitnesses became less accurate as they moved through the lineup. An individual placed in the first position was more likely to be correctly classified (as either the suspect or a foil) than in the second, third, and so on; the decline appears linear in nature. Police departments should appreciate that sequential lineups may reduce the accuracy of eyewitness identification and could result in falsely imprisoning the innocent or the failing to capture the guilty.


Wilson, Brent, Kristin Donnelly, Nicholas Christenfeld, and John Wixted (2019), “Making Sense of Sequential Lineups: An Experimental and Theoretical Analysis of Position Effects,” Journal of Language and Memory, 104, 108-125.