Research has shown that the speed and coherence of speech in infants and songbirds depend not only on physical practice but also on social approval. It was found that both children and young birds begin to produce sounds more quickly when adults respond to their attempts at communication. These findings suggest that the development of complex forms of communication is closely linked to seeking social feedback.

Human speech and birdsong are composed of sequences of sounds. As children and chicks grow, they start to produce these sounds faster, shortening the intervals between syllables. Previously, it was believed that this process was driven solely by practice. However, new research suggests that the reactions of those around them play a key role in the development of speech.

During the experiments, researchers studied infants and zebra finches (Taeniopygia guttata). In the first study, they observed how five- and ten-month-old children interacted with their parents at home. The analysis focused on which sounds parents responded to more often—single sounds or sequences of syllables. The children’s vocabulary at the age of one and a half was also assessed.

In another experiment, young zebra finches were shown videos of an adult female displaying approval of a male’s courtship song. The chicks were divided into two groups: the first group saw the video only during their singing attempts, while the second group saw it at random times. This way, both groups had the same motor practice and visual stimuli, but only the first group experienced a direct connection between singing and social reward.

The results confirmed the hypothesis about the influence of social feedback. Parents of infants responded to syllable chains almost ten times more often than to single sounds. Children who received responses to their communication attempts at five months of age developed speech faster and, by ten months, demonstrated a higher speech rate. Their speech development also correlated with a richer vocabulary at one and a half years old, while the total number of sounds produced did not affect vocabulary growth.

The experiment with birds yielded similar results. Finches that received a female’s reaction to their singing increased their singing speed and stabilized their rhythm more quickly. Chicks in the control group, who saw the video at random times, did not learn to sing quickly and smoothly, even though they sang as much as the others.

The study showed that social approval encourages not only sound production but also denser and faster speech. The evolution of communication is based on the search for social feedback, and fluent, rapid speech develops precisely because it elicits a response from the surrounding community.