Animals, not just humans, exhibit rhythm-synchronized behaviors with individuals in the population, but while non-human animals exhibit rhythm-synchronized behaviors that are unstable, uncertain, and short-lived, humans exhibit rhythm-synchronized behaviors with other individuals. It can be done extremely quickly, accurately and sustainably.In order to verify when and how these human-specific abilities develop, in this study, 18-month-old, 30-month-old, and 42-month-old infants are "taikoed with their partner (mother / robot)." I presented the scene and examined the ability to synchronize with the rhythm of the other party.

　As a result, at the age of 18 months, there is already an action to control one's own tapping according to the opponent's "fast rhythm", and in some cases, only when the mother is the opponent, "slow rhythm". However, the behavior to match was confirmed.After 30 months of age, he began to adapt flexibly and accurately to the rhythm of the other party.

　From this, if the rhythm is easy for you to perform (it can be dealt with by motor function in the early stage of development), synchronization with the other party can be seen from the early stage, and the behavior is promoted by social bonds, 30 months after birth. It was shown that the ability to flexibly and accurately adjust to the rhythm of the other party becomes apparent.

　This study revealed that the ability to synchronize with the partner's rhythm gradually emerges, closely related to the social development seen in the 18th to 30th months of life.The ability to act in rhythm with the other person is thought to have important survival implications for humans who have evolved while building complex social groups.In the future, the sprouting of synchronous behavior of babies before 18 months of age will also be the subject of research by this group.

Paper information:[Infancy] The early development of tempo adjustment and synchronization during joint drumming: A study of 18- to 42-month-old children