Children's Understanding of Emotion in Speech

Can children detect sarcasm? Can children detect the emotion of a speaker? Morton and Trehub published an article in volume 72 of Child Development that seeks to answer this question. In their article they explore the ability of children to detect emotion in speakers through paralinguistic cues. Paralanguage can be described as non-verbal elements of communication such as pitch, volume, rhythym, gestures and other cues. So the question they asked the question: Do children tend to focus more on the content of utterances, or the underlying paralinguistic aspects of voice sounds? This was tested in three experiments.

           

The first experiment consisted of 120 participants. 100 of them were divided between 4 and 10 years old. The remaining 20 were young adults, mostly college students. They were each given 20 utterances, 10 with happy content and 10 with sad content. However, the happy content used sad paralanguage (lower pitch, attenuated pitch, slower speaking rate) and the sad content used happy paralanguage (higher pitch, greater pitch and loudness variation, and faster speaking rate as compared to the sad paralanguage). The participants were asked to judge if an utterance was happy or sad by saying so or pointing to a sign with a happy face or sad face. The results showed that the 4 year olds were most likely to judge the emotion of an utterance based on content and that adults almost always judged emotion based on paralanguage. The results showed that 10 year olds were more likely than younger children to judge emotion based on paralanguage. There seemed to be a correlation between age and the use of paralanguage in determining emotion.

The second experiment was conducted to decide whether the youngest children (four year olds) were able to judge paralanguage in speech at all. To do this, the experimenters recorded utterances in Italian, so the children would not understand the content, and played them to the children, who were asked to tell if the utterance was happy or sad. The employment of happy vs. sad paralanguage that was described in experiment one was used here as well. The participants were all four-year-olds (8 boys and 12 girls).  The results showed that the children performed better than 80% correct. Some of the children had a tendency to alternate between the two options due to shyness, boredom, etc. When these results were discarded, the children performed better than 90% correct. The results of this second experiment seem to suggest that children are very capable of using paralanguage to determine emotion.

The third experiment attempted to determine whether young children also understood the paralanguage in the utterances from experiment one. To do this they pass-filtered the utterances, which destroys many of the phonetic clues and makes the content largely unintelligible, while preserving the paralinguistic clues of pitch, volume, and speed. 20 four-year-olds, 20 five-year-olds, and 20 six-year-olds were used (half male and half female). The results showed that children as young as four were able to pick up on paralinguistic cues. The six-year-olds did better than the two other groups. It is unclear whether or not this is due to better perception of paralanguage or greater ability to sit through a mundane task.

Summary
What's very interesting here is that young children seem to have the ability to decode emotion in utterances by using paralinguistic cues. However, the youngest children studied, when content and paralanguage conflicted, almost invariable trusted the content over the paralanguage.