In a Monte Carlo casino in 1913, during a game of roulette, something incredible happened: the ball fell on black 26 times in a row.

Gamblers lost millions of francs that day because, as the black streak continued, they assumed the next roll would land on red. While the odds of the ball landing on black 26 times in a row are low – around one in 66 million – for each individual spin the odds are one in two. Every new spin of the roulette wheel has the same chance, regardless of what happened earlier.

This event coined the term “gambler’s fallacy” to describe the mistaken belief that past occurrences change the risk of future incidents. The insight this fallacy provides into how people respond to rare events may have important lessons for injury researchers.

In a new study, BC Children’s Hospital researchers investigated whether parents fall victim to the same fallacy when they assess their child’s risk of getting hurt. We spoke with Takuro Ishikawa, a UBC doctoral candidate working under Dr. Mariana Brussoni in the BC Injury Research and Prevention Unit at BC Children’s Hospital, on his new publication in Preventive Medicine Reports and how his findings could help improve how health care professionals talk to parents about risk.

Takuro Ishikawa
Takuro Ishikawa
Dr. Mariana Brussoni
Dr. Mariana Brussoni
What was the goal of this research?

Some injury prevention researchers have suggested that if parents learn about injury prevention around the same time they are worried about their children getting hurt, then they’re more likely to act on those prevention methods. For example, if parents are informed about the risks of falling down the stairs when their children are first walking, they’re more likely to install safety gates in their home.

In this study, we looked at how parents’ concerns about their child getting hurt again changed in the year after their child was admitted to the emergency department for an injury. If parents are most concerned at the time of the initial injury, we would expect their perception of risk to decrease over time. If on the other hand, parents’ perception of risk is susceptible to the “gambler’s fallacy” then their concern over re-injury might actually increase as the weeks or months go by.

In this scenario, like the Monte Carlo casino, a parents’ belief in the likelihood their child will get hurt increases each time they play on the monkey bars, practice hockey, or ride in a car. The more times the child is involved in these activities without incident, the more likely parents would believe they will be injured in the near future.

Of course, the actual risk of injury isn’t based on luck, but is instead influenced by the behavior of the child or parents, the quality of the playgrounds, or the safety of the roads.

But if parents believe that injuries are subject to chance, and that this chance increases over time, then teaching parents about injury prevention the day their children get hurt might not be an effective approach. Instead, preventative strategies should be discussed in the weeks or months after an injury rather than in the emergency department itself. 

How did you try to figure this out?

We approached parents in the Emergency Department at BC Children’s after their kids had been treated. We asked them how likely they thought it would be for their child to be injured again. Then, we measured parents’ perception of risk using a seven-point scale ranging from “very low” to “very high”. Participating parents were then asked to fill out follow-up questionnaires one, four and 12 months after the initial visit.

When the questionnaires were returned, we tracked how the parent’s perception of risk had changed from the day of the injury up to a year later.

What were the findings?

The perceived risk of injury initially rose over a period of six weeks, but over the course of the following year, it dropped back down.

These findings don’t precisely hold to our initial gambler’s fallacy hypothesis – that parent’s perceived risk of injury would continue to increase in the weeks and months following an injury – but they do show that parents’ perception of risk changes over time.

One possible explanation of the findings is that immediately after a child is admitted to hospital with an injury, parents think it is unlikely that the same injury would occur again. But as the weeks go by, parents concern over re-injury increases, perhaps believing that their child is “running out of luck.”

Our results suggest that their concern peaks around six weeks and then begins to slowly wane.

What does this mean for kids?

These results show that talking to parents a few weeks after an injury may be a more effective way to communicate risk than right after an injury happens. This is the period when parents are more likely to be concerned about their children being injured again. For example, a better time to talk to the family about preventing future injuries may be when the child comes back to the hospital for a follow up visit or to have a cast removed.

Helping parents prevent kids from getting hurt can reduce the amount of time children and their families have to spend in hospitals, and reduce the likelihood of children having serious injuries that result in lifelong disability or death.

It’s also important that parents are aware that preventing injuries does not mean preventing play. Outdoor risky play is vital for children’s healthy development, including greater physical activity, self-confidence and risk management skills.

The next step of this research is to use a randomized control trial to determine whether four or six weeks after their child is admitted to the emergency department would be a better timeframe to engage parents.

What got you into the world of risk perception and child health?

I had a background in psychology and began working as a consultant doing risk analysis for various organizations such as pension funds. But I really enjoyed it when I started doing risk analysis in injury prevention.

I am also fascinated by how humans understand and interpret risk. We have two different ways of thinking about risk. Sometimes, we think of risk in logical terms, based on data, but other times we rely heavily on our gut feelings and emotions.

For example, parents are often overly afraid of unlikely risks such as abduction. In response to this fear, they may limit children’s opportunities to engage in developmentally beneficial activities like risky play. Yet at the same time, parents are rarely concerned about driving their kids around in the car which, statistically speaking, is far more dangerous.

Understanding injury risk is both challenging and important and I find using this research to help children avoid unnecessary injuries while encouraging healthy childhood activities to be incredibly rewarding.