First, there is the stage of Primar

First, there is the stage of Primary intersubjectivity, or the mental representa-
tion of self-and-other, which is the key to the human form of communication (Trevarthan 1988). The child's first expressions are very often emotionally
based. Through a process of interaction with the caretaker (often the mother but
not necessarily), the child as it were, learns the power of gestures. For example, the repeated pushing of the caretaker's hands under the child's armpits when the child is being picked up leads the child to anticipate being picked up. Later, the caretaker needs only to stand in front of the child for the child to raise his or her arms in expectation of being picked up (Lock 1978).

Hasil (Bahasa Indonesia) 2:

Pertama, ada tahap intersubjektivitas Primer, atau mental-wakil
tion diri dan-lainnya, yang merupakan kunci untuk bentuk manusia komunikasi (Trevarthan 1988). Ekspresi pertama anak sangat sering emosional
berdasarkan. Melalui proses interaksi dengan caretaker (sering ibu tapi
belum tentu), anak karena itu, belajar kekuatan gerakan. Misalnya, berulang-ulang mendorong tangan penjaga di bawah ketiak anak ketika anak sedang dijemput mengarah anak untuk mengantisipasi dijemput. Kemudian, penjaga hanya perlu berdiri di depan anak bagi anak untuk meningkatkan nya senjata di harapan dijemput (Lock 1978).