In our day-to-day lives, we are faced with several different kinds of threats. If our species is to survive, we need to develop ways to cope with these threats quickly and efficiently. But how do we learn what is safe and what is dangerous? In my lab, we study how humans, especially children, respond to imminent threat. More precisely, we are studying a threat that we all face every single day: the threat of getting sick.

Indeed, we’ve all had the experience of feeling sick, perhaps having a cold, and many of us have even battled something more serious, like the flu. If you have young children at home, you’re no doubt aware that children not only have less developed immune systems, but they are also more likely than adults to spread illness to others. Research suggests that children don’t really know much about illness or how it spreads until late in the preschool years.

Until recently, very few studies have examined how children behave when faced with the threat of getting sick. This is important, as behavior when confronted with a sick person or a contaminated object is what is most likely to determine if children actually get sick, and whether they are likely to spread that illness to others.

“Children as young as four and five are capable of behaving adaptively if we give them the right information.”

Recently, we began a new program of research to find out when children actively avoid contact with sick individuals and contaminated objects, and to identify factors that may drive children’s avoidance behavior. In one study, we introduced four- to seven-year-olds to two adults, one of whom was described as having a cold. The adults then gave each child an identical set of toys. After the children were allowed to play freely with all of the toys for five minutes, we asked them a series of questions to assess their knowledge of illness transmission.

We found that the older children (six- and seven-year-olds) spent significantly more time playing with the healthy experimenter’s toys, while the younger children were happy to play with either set, whether or not they might have been contaminated.

But age wasn’t the best predictor of avoidance behavior. Instead, the most reliable indicator of whether a child would avoid the sick experimenter’s toys was the ability to correctly predict whether or not someone might get sick, based on that person’s previous actions. Importantly, this held true for both the older and the younger kids, but the younger ones were less likely to know this information. The implication here is that younger children are capable of acquiring accurate knowledge about illness transmission – most of them just haven’t yet.

In some ongoing research, we are now exploring whether we can teach younger children (aged three to five) to avoid contaminated toys by providing them with information about illness transmission. In one study, we divided children into four groups and read each group a picture book about a fictional character named Prudence, who becomes sick in the story. Three groups were given three different explanations for how she got sick – biological (i.e., germs got onto her toys), physical (i.e., she sat next to someone who was sick), or behavioral (i.e., she was mean) – and the fourth was given no explanation at all.

After reading the book, we invited the children to choose a toy to take home with them as a reward for helping us with the study – one that had been played with by a child who had a “cold” (contaminated), or one that had been played with by a child who had a “toothache” (non-contaminated). Only the children who had been given the biological explanation for Prudence’s illness – that germs got onto her toys – consistently chose to take home the non-contaminated toy.

In a follow-up study, we are currently asking whether information about the presence of germs is enough to drive avoidance behavior or whether children need very specific information about how germs can be transferred to toys in order to show healthy avoidance.

Altogether, our research thus far suggests not only that children do indeed actively avoid contact with sick people and potentially contaminated objects, but also that children as young as four and five are capable of behaving adaptively if we give them the right information. We are hoping to continue this line of work and eventually to use our findings to make practical recommendations about teaching children to play an active role in their own disease prevention.


The Cognitive Development Society (CDS), which aims to provide a unified voice for the wide range of scholars, practitioners, and others who are interested in change and continuity in the intellectual processes that support mental life, held their 2017 biennial meeting in Portland, Oregon, on October 12-14. The program included cutting-edge research on analogy, imagination, executive function, risk perception, spatial cognition, numerical cognition, moral cognition, causal inference, and language development. More information about the program can be found here.


The author of this blog post, Vanessa LoBue, will be joining her colleagues and students – Dr. Megan Geerdts, Zachary Walden, and Emily Kim – in presenting their findings and others at the CDS Conference.

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