TY - JOUR A1 - Guo, G. A1 - VanWey, L.K. T1 - Sibship Size and Intellectual Development: Is the Relationship Causal? Y1 - 1999 DO - 10.2307/2657524 JF - American Sociological Review VL - 64 IS - 2 SP - 169 EP - -187 ER -