The dialogical self theory's (DST) growing importance and increasing multidisciplinarity have resulted in elaborating several developmental issues: in infancy, in young adults, and regarding significant processes such as cultural transition and motherhood. The chronology given is thus an approach with hints to significant moments within the first two years of life and a glimpse into further development. The dialogical quality of the infant's activities is correlated with heart rate: provocative imitations are shown to be anticipated by heart deceleration indicating preparation for an expected stimulus. Timing and taking up the other's bodily performance show time and form as supports of earliest proto-conversations between partners on the body level. Self comes to be within the rhythm of intersubjectivity, first in a fully concrete sense. DST is different from other self theories in the respect that it opens up to the rhythmicity of selfness-otherness, forming a dynamic unity.