Why are we so afraid to leave children alone?

"Without realizing it, we have consistently increased our estimates of the amount of danger facing children left alone in order to better justify or rationalize the moral disapproval we feel toward parents who violate this relatively new social norm," said Ashley Thomas, cognitive sciences graduate student and lead author of the work, published online this month in the open-access journal Collabra.

The survey-based study found that children whose parents left them alone on purpose -- to go to work, help out a charity, relax or meet an illicit lover -- were perceived to be in greater danger than those whose parents were involuntarily separated from them.

The researchers presented survey participants with five different scenarios in which a child was left alone for less than an hour. Situations ranged from a 10-month-old who was left asleep for 15 minutes in a cool car parked in a gym's underground garage to an 8-year-old reading a book alone at a coffee shop a block from home for 45-minutes.

"Within a given scenario, the only thing that varied was the reason for the parent's absence," said Kyle Stanford, professor and chair of logic & philosophy of science. "These included an unintentional absence -- caused by a fictitious accident in which the mother was hit by a car and briefly knocked unconscious -- and four that were planned: leaving for work, volunteering for a charity, relaxing or meeting an illicit lover. After reading each scenario and the reason behind each child being left alone, the participants ranked on a scale of 1 to 10 how much estimated danger the child was in while the parent was gone, 10 being the most risk."

Overall, survey participants saw all of these situations as quite dangerous for children: The average risk estimate was 6.99, and the most common ranking in all scenarios was 10. Despite identical descriptions of each set of circumstances in which children were alone, those left alone on purpose were estimated to be in greater danger than those whose parents left them alone unintentionally.

"In fact, children left alone on purpose are almost certainly safer than those left alone by accident, because parents can take steps to make the situation safer, like giving the child a phone or reviewing safety rules," said Barbara Sarnecka, study co-author and associate professor of cognitive sciences. "The fact that people make the opposite judgment strongly suggests that they morally disapprove of parents who leave their children alone, and that disapproval inflates their estimate of the risk."

This is also born out in participants' view of children left alone by a parent meeting an illicit lover as being in significantly more danger than children left alone in precisely the same circumstances by a parent who leaves in order to work, volunteer for charity or just relax.

In scenarios where participants were asked to judge not only how much danger the child was facing, but also whether the mother had done something morally wrong, researchers expected the perceived risk ranking to be lower.

"We thought giving people an alternative way to express their disapproval of the parent's action would reduce the extent to which moral judgments influenced perceptions of risk," Thomas said. "But just the opposite happened. When people gave an explicit judgment about the parent's conduct, estimates of risk to the child were even more inflated by moral disapproval of the parent's reason for leaving."

In fact, people's risk estimates closely followed their judgments of whether mothers in the scenarios had done something morally wrong. Even parents who left children alone involuntarily were not held morally blameless, receiving an average "moral wrongness" judgment of 3.05 on a 10-point scale.

The authors found another interesting pattern when they replaced mothers in the stories with fathers: For fathers -- but not mothers -- a work-related absence was treated more like an involuntary absence. This difference could stem from the view that work is more obligatory and less of a voluntary choice for men.

"Exaggerating the risks of allowing children some unsupervised time has significant costs besides the loss of children's independence, freedom and opportunity to learn how to solve problems on their own," Sarnecka said. "As people have adopted the idea that children must never be alone, parents increasingly face the possibility of arrest, charges of abuse or neglect, and even incarceration for allowing their children to play in parks, walk to school or wait in a car for a few minutes without them."

"At a minimum," she continued, "these findings should caution those who make and enforce the law to distinguish evidence-based and rational assessments of risk to children from intuitive moral judgments about parents -- and to avoid investing the latter with the force of law."

The study involved survey responses by 1,328 participants on Amazon Mechanical Turk ranging in age from 18 to 75, with a fairly even split of men and women and those with and without children. Females accounted for 52 percent of respondents, while 48 percent were male; and 56.43 percent had children, while 43.57 percent did not. More than 80 percent of the participants were white, and two-thirds had completed at least some college.