Duke University conducted a study to find out why girls are more vocal than boys and have a better vocabulary at a younger age than boys. The researchers theorized that this difference was because caregivers spoke more to girls than boys and conducted this study to evaluate their theory. However, they soon discovered this wasn’t the case. Instead, caregivers said more to babies who were already vocal.
For their study, researchers listened to more than 2000 recordings documenting infants’ daily lives. They believe that their research has shed light on the subject of language development in children.
Girls develop their vocabularies earlier than boys
According to Dr. Shannon Dailey, a study author from Duke University, the study shows that children impact their language environments. Erika Bergelson, a professor of psychology and neuroscience at the university and co-author of the study, adds that girls typically exhibit a better vocabulary than boys at a young age. For this reason, speech delays are more common in boys, so many researchers have tried to find out why.
The study authors initially believed that the advantage girls temporarily had over boys in language was due to receiving more input from their caregivers.
How researchers conducted the study
The study authors evaluated 44 children for one year from six months. These children included 23 boys and 21 girls. The team chose this age to begin the study as it would enable them to track the children’s language input before they started talking to about 18 months, when most children have started speaking.
Once a month, the babies would wear colorful vests with an audio recorder recording about 16 hours of audio. On a different day each month, they would then wear a cap with a small camera to record video. The researchers would take audio from these videos to use for their study. By the end of the research, they had about 8976 hours of sound.
Researchers counted the number of unique nouns that the babies spoke. They realized that boys and girls said the same amount; thus, their vocabulary wasn’t due to more practice. However, parents would speak more to their babies when they started to talk.
