Adults and children judge coincidences differently, study reveals

Coincidences—unexpected confluences of events that seemingly defy probability—captivate people across cultures and ages. New research published in Cognition sheds light on the cognitive mechanisms underpinning the recognition of coincidences and how these mechanisms evolve as we grow older.

The cognitive mechanisms involved in representing coincidences are thought to be part of broader causal reasoning processes. Research suggests that even preschool-aged children demonstrate flexible causal reasoning abilities, adjusting their inferences based on how data is generated and exploring more when causal relationships are ambiguous. Despite these early-emerging capacities, it remains unclear whether young children can distinguish between mere coincidences and causally linked events, as adults do.

Experiment 1 involved 117 English-speaking adults aged 18 to 74 recruited through Amazon Mechanical Turk and Prolific. Participants read eight short vignettes, each describing a set of co-occurring events. The vignettes were designed to either include or exclude information that could potentially explain the co-occurrences.

The number of co-occurring events also varied across vignettes, with scenarios involving two, three, a few, or all events co-occurring. For each vignette, participants rated how surprising they found the events (on a 4-point scale), whether they considered the events to be a coincidence and whether they believed there was a reason for the co-occurrence (on binary scales). Participants’ demographic information and responses to additional exploratory questions about belief in supernatural powers, religious practices, and frequency of noticing coincidences were also collected.

Qiong Cao and Lisa Feigenson found that judgments of coincidences were influenced by the presence of explanations and the number of co-occurring events. Participants were more likely to judge events as coincidences when no explanations were provided. When explanations were present, they were more likely to believe there was a reason for the events’ co-occurrence and rated the events as less surprising. When no explanation was available, coincidence ratings initially increased with the number of co-occurring events but then decreased when all events co-occurred, suggesting that too many co-occurrences prompted them to infer an underlying causal explanation.

Experiment 2 involved 94 children aged 4 to 10 years, tested in a university child development laboratory or a local science museum. The vignettes used in Study 1 were adapted for children, with the number of vignettes reduced to four to maintain attention. The vignettes varied in the presence of potential explanations and the number of co-occurring events, similar to the adult study. They were read aloud by an experimenter, accompanied by simple illustrations to help children understand the events. After each vignette, children rated how surprising they found the events using a pictorial scale featuring cartoon faces and answered whether they thought the events were a coincidence and if there was a reason for the co-occurrence.

The results indicated that even the youngest children were sensitive to the presence of explanations, showing a basic understanding of coincidences. When no explanations were provided, children were more likely to judge the events as coincidences, believe there was no reason for the events’ co-occurrence, and find the events more surprising.

However, only older children (7 to 10 years old) showed sensitivity to the number of co-occurring events similar to adults. Older children’s coincidence ratings initially increased with the number of co-occurring events but decreased when all events co-occurred, whereas younger children (4 to 7 years old) did not show this sensitivity.

These findings suggest that the cognitive mechanisms underlying coincidence recognition are present early in life but become more refined with age and experience.

One limitation noted by the authors is the reliance on verbal explanations and judgments, which might have influenced younger children’s responses due to their developing language skills.

The research, “Children’s Representation of Coincidence”, was authored by Qiong Cao and Lisa Feigenson.