Abstract
The purpose of this study is to make clear how to develop of laughter and smile in infants on the bases of the observation data on children's behaviors in a day nursery for 6 years. This report described the characters of 2 year old children's laughter and smile after 1 year old children's.
The characters were as follows :
(1) Similarly to 1 year old children, 2 year old children's laughter and smile were observed in 3 lebels : body, cognition and society. And the 3 lebels were not independent but related to each other.
(2) They became to be able to use laughter and smile actively in relation with other persons.
(3) The smile concerning with “understanding” increased, and they became to laugh “funniness.”
(4) They didn't get clear social consciousness, but the laughter and smile concerning with their self-consciousness through the other persons emerged.
