In infancy, caregivers rely on facial expressions and vocal cues to understand a baby’s needs and emotions, as babies do not use language.
Research shows that while facial expressions are important, they are less effective than vocal and cognitive signals. Adults tend to focus more on a child’s voice when assessing emotional states and vulnerability, but they use cognitive content, such as reasoning abilities, to gauge intelligence.
When a child’s vocal immaturity conflicts with advanced cognitive abilities, caregivers prioritize vocal signals for emotional needs and cognitive signals for intelligence. This underscores how different signals influence judgments in early childhood.
Compared to other mammals, human infants depend on their caregivers for an exceptionally long time. Over the centuries, they have developed “psychological tactics” to become endearing to adults and thereby increase their survival chances. This prolonged dependency is believed to have led to the evolution of complex signaling mechanisms that help infants attract and maintain adult attention. As babies grow, their communication methods evolve from simple cries and facial expressions to more sophisticated vocal and cognitive signals.
Research has shown that when children are young, adults are drawn to certain signs of immaturity in their voices and thoughts, which help them understand what the children need. A key question that has not been thoroughly studied is how caregivers weigh vocal versus cognitive cues in early childhood. For example, if a child’s voice sounds immature but their reasoning is advanced, which aspect influences caregivers more?
To address this, researchers from Florida Atlantic University and Universitat Jaume I in Spain examined how adults interpret these signals and the dynamics between different types of cues, such as facial expressions, voices, and cognitive signals.
The researchers created two main scenarios: one where a child’s vocal and cognitive cues matched (consistent condition) and another where they did not match (inconsistent condition). For example, in a consistent condition, a child might display an immature voice and magical thinking, where they believe their thoughts or actions can unrealistically influence the world. In contrast, an inconsistent condition might present a child with mature reasoning but an immature voice.
Study participants listened to recordings of children speaking while researchers examined their responses to these children. They focused on two types of cues: how the children’s voices sounded and how they reasoned.
The study’s results, published in Evolution and Human Behavior, found that adults pay more attention to children’s voices when evaluating their happiness or vulnerability. However, when assessing a child’s intelligence (related to magical thinking) or negative emotions (related to physical thinking), adults focus more on the content of what the child says rather than the tone of their voice.
“When vocal and cognitive cues aligned, children with immature voices and magical thinking were perceived as more helpless, while those with mature voices and logical thinking were seen as more intelligent and less helpless,” said David Bjorklund, Ph.D., co-author, and Associate Chair and Professor in the Department of Psychology at FAU.
He added, “When cues were conflicting, adults relied more on vocal signals, especially for assessing emotions and vulnerability. This demonstrates how vocal signals significantly influence emotional judgments and perceived caregiving needs, reflecting the sophisticated ways in which children use these signals to elicit care.”
During infancy, children do not use language, so caregivers heavily rely on facial and vocal cues to assess their needs and emotions. For example, a baby’s cry or facial expression may signal hunger or discomfort, helping caregivers respond appropriately.
Interestingly, when evaluating intelligence, adults seemed to rely more on cognitive cues rather than vocal ones. For children expressing physical thinking, the maturity of their reasoning had a significant impact on judgments of their intelligence. However, this was not always the case. For supernatural or magical reasoning, the influence of cognitive and vocal cues was more mixed, suggesting that the interaction between these signals may vary depending on the context.
“Our research shows that while facial expressions remain important, they are less effective at conveying certain types of information compared to vocal and cognitive signals,” said Bjorklund. “Understanding these dynamics can improve comprehension of caregiver-child interactions and inform approaches to support both children and caregivers.”
