A groundbreaking new study led by Michigan State University researchers has revealed that sleep-deprivation increases the likelihood of people signing false confessions as compared to rested individuals. In particular, the odds of signing a false confession were a whopping 4.5 times higher for participants who had been awake for 24 hours as compared to those that slept eight hours the night before, which could have important implications for current police interrogation practices.
"This is the first direct evidence that sleep deprivation increases the likelihood that a person will falsely confess to wrongdoing that never occurred," Kimberly Fenn, who participated in the research, said in a press release. "It's a crucial first step toward understanding the role of sleep deprivation in false confessions and, in turn, raises complex questions about the use of sleep deprivation in the interrogation of innocent and guilty suspects."
The study monitored and analyzed 88 participants, who completed various computer activities as well as a cognitive test, over the course of numerous laboratory sessions. This took place over the span of one week, during which they were given several warnings to never hit the "escape" key because it would "cause the computer to lose valuable data."
During the final day of the experiment, half of the participants stayed awake overnight while the other half slept for eight hours. Before leaving the lab the following morning, they were shown a statement that falsely alleged that they pressed the escape key during the course of the experiment and asked to confirm the accuracy of the statement by checking a box and signing their name.
The result showed that 50 percent of the sleep-deprived group signed the false confession, whereas only 18 percent of the rested participants signed it. Further analysis revealed that sleep deprivation also had an effect on participants who scored lower on the Cognitive Reflection Test, which has been shown to be associated with intelligence - these participants showed an increased likelihood of signing the false confession when sleep deprived.
"A false admission of wrongdoing can have disastrous consequences in a legal system already fraught with miscarriages of justice," the authors conclude in the paper. "We are hopeful that our study is the first of many to uncover the sleep-related factors that influence processes related to false confession."
The findings were published in the Dec. 30 issue of the Proceedings of the National Academy of Sciences.
