Uncommon Knowledge

An invisible gorilla in your lungs

And other surprising insights from the social sciences

Gorillas in your torso

In a famous experiment, researchers asked people to watch a video of a group passing a basketball and count the number of passes. In the middle of the video, someone in a gorilla suit unexpectedly walks through the group—but many viewers fail to notice the gorilla, because they’re so focused on counting passes. In a new experiment, researchers with Harvard Medical School’s Visual Attention Lab have taken this work on “inattentional blindness” one step further. They asked radiologists to look for nodules in a CT scan of a lung. Unbeknownst to the radiologists, the scan also contained an image of a gorilla, such that “if someone pointed at the correct location in the static image and asked you, ‘What is that?’ you would have no trouble answering, ‘That is a gorilla.’” Yet most of the radiologists failed to notice the gorilla, even though many of them looked directly at its location. The good news is that “radiologists were much better at detecting lung nodules (mean detection rate = 55%) than were naive observers (12%).”

Drew, T. et al., “The Invisible Gorilla Strikes Again: Sustained Inattentional Blindness in Expert Observers,” Psychological Science (forthcoming).

How to feel tiny

Ever wish you could return to childhood? You can now make that a (virtual) reality. In an experiment, participants donned virtual reality gear that put them in the body of either a small child or an adult scaled down to the same height as the child. When embodied as a child, participants more readily overestimated the sizes of objects and implicitly identified with children
rather than adults, compared to being embodied as a scaled-down adult. These effects were eliminated when the movements of the virtual body were made to be asynchronous—and thus disconnected—with the movements of the participants.

Banakou, D. et al., “Illusory Ownership of a Virtual Child Body Causes Overestimation of Object Sizes and Implicit Attitude Changes,” Proceedings of the National Academy of Sciences (forthcoming).

Get off easy, reoffend

As the saying goes, the punishment should fit the crime. What happens when it doesn’t—in the eyes of the offender? An analysis of convictions in Maryland before and after a change in sentencing recommendations found that higher recommended sentences led to higher recidivism rates, even though actual sentences and time served remained the same. The theory behind this is that the recommended sentence—“conveyed to a defendant during conversations with his lawyer, during the judge’s statement at
sentencing, or through a peek at his criminal file during a parole evaluation”—is a benchmark for the offender to judge the relative harshness of the judicial system. So a higher recommended sentence may make the offender think he got off easy.

Bushway, S. & Owens, E., “Framing Punishment: Incarceration, Recommended Sentences, and Recidivism,” Journal of Law and Economics (May 2013).

Fear: it’s in your sweat


Deodorant commercials once warned: “Never let them see you sweat.” Based on new research, though, you may not want to let them smell you sweat, either—because if you’re afraid, it will be just as obvious. Researchers collected sweat from young men while they watched fear-inducing or neutral videos. The researchers then exposed young women to the sweat while they too watched fear-inducing or neutral videos. Fear-generated sweat was just as potent in eliciting fearful facial expressions as the fear-inducing videos.

de Groot, J. et al., “I Can See, Hear, and Smell Your Fear: Comparing Olfactory and Audiovisual Media in Fear Communication,” Journal of Experimental Psychology: General (forthcoming).

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You know those thermometers on charity websites that fill up as the donation goal approaches? It looks like they have a real effect—and, if you run a charity, it seems you might want to consider shooting for an attainable target and raising the goal as you go. Those are the implications of a new study, which found that people were more likely to donate when fund-raising goals were closer to being reached.

Cryder, C. et al., “Goal Gradient in Helping Behavior,” Journal of Experimental Social Psychology (forthcoming).

Kevin Lewis is an Ideas columnist. He can be reached at