Key points are not available for this paper at this time.
Thomas J. Berndt, Jacquelyn A. Hawkins, Sally G. Hoyle, Changes in Friendship during a School Year: Effects on Children's and Adolescents' Impressions of Friendship and Sharing with Friends, Child Development, Vol. 57, No. 5 (Oct., 1986), pp. 1284-1297
Berndt et al. (Wed,) studied this question.