Key points are not available for this paper at this time.
Yuriko Oshima-Takane, Elizabeth Goodz, Jeffrey L. Derevensky, Birth Order Effects on Early Language Development: Do Secondborn Children Learn from Overheard Speech?, Child Development, Vol. 67, No. 2 (Apr., 1996), pp. 621-634
Oshima‐Takane et al. (1996) studied this question.