Field, T., Widmayer, S., Adler, S., & De Cubas, M. (1990). Teenage parenting in different cultures, family constellations, and caregiving environments: Effects on infant development. Infant Mental Health Journal, 11(2), 158-174.
Teenage mothers are still kids, they want the attention of adults . Same is the case for their infants. Children compete for an adults attention (Zajonc and Markus, 1975). Also, if the mother's family have younger members they automatically take the role of 'siblings' (Dunn
& Kendrick, 1979).