Research Watch

Intervention to enhance language development of toddlers in foster care

Year of Publication
Reviewed By
Marianna Healey

Lee Raby, K., Freedman, E., Yarger, H.A., Lind, T., & Dozier, M. (2018). Enhancing the language development of toddlers in foster care by promoting foster parents’ sensitivity: Results from a randomized controlled trial. Developmental Science, e12753.


Children living in foster care are at risk for impaired language development. Parent-delivered early interventions focused on parental sensitivity have been found to improve the language development of young children. These improvements have been thought to occur via the effects of sensitive parenting on children’s motivation to communicate as well as children’s communication abilities, since children exposed to sensitive parenting receive a higher quantity of verbal input. The authors of this study sought to enhance the language development of young children living in foster care by coaching foster parents to deliver a sensitivity-based intervention developed specifically for young children who had experienced adversity (Attachment and Biobehavioral Catch-up for Toddlers; ABC-T). The efficacy of an infant version of this intervention has previously been established for infants living in foster care. In the current study, the efficacy of the ABC intervention was evaluated for an older group of children (toddlers aged 24-36 months).

In this study, foster parents of toddlers living in foster care were randomized to either receive the ABC-T program (n = 45) or a control intervention (n = 43) of comparable length that was not focused on sensitive parenting (Developmental Education for Families; DEF). Both interventions included 10 weeks of in-home coaching of a manualized intervention. Clinicians (“parent coaches”) were trained in one of the two interventions, video-recorded for fidelity, and blinded to which intervention was the experimental condition. Caregivers receiving either intervention were video-recorded interacting with their child during semi-structured play opportunities prior to receiving the intervention, immediately after receiving the intervention, and at key follow-up points. These videos were coded for sensitivity by blinded, reliable coders. Children’s receptive vocabulary abilities were measured using the Peabody Picture Vocabulary Test-Third Edition (PPVT) at approximate ages of 36, 48, and 60 months.

Foster parents who received the ABC-T demonstrated more sensitive caregiving than foster parents who received the control condition. Children whose foster parents received the experimental intervention (ABC-T) also demonstrated more advanced receptive vocabulary abilities compared to children whose foster parents received the control intervention. The positive effect of the ABC-T intervention on the toddlers’ receptive vocabulary skills was mediated by the foster parents’ sensitive caregiving.

Methodological Notes

One limitation of this study is the lack of assessment of the toddlers’ pre-intervention vocabulary skills. The Peabody Vocabulary Test can only be administered to children 30 months and older, so children did not complete this measure when beginning the intervention prior to this age. However, there were no notable differences in demographic characteristics of children or foster parents in the experimental and control conditions. Further, there were no differences in the foster parents’ sensitivity ratings prior to intervention. These factors increase the ability to have confidence in attributing post-intervention differences in children’s skills to the intervention’s effects. Another limitation of this study is the attrition rate; although 205 families were originally consented to the study, only 88 families completed enough of the study to be included in the final analyses. Among these 88 participants, not all children completed the research or video follow-up visits at each time point (n ranged from 32 to 58 children for the follow-up visits at 36, 48, and 60 months). Although attrition analyses showed no differences between families who were and were not retained in the study sample, the families included in the final data set arguably represent a more stable subset of families in foster care. More research is needed to understand how well these findings generalize to a broader set of foster families, as well as the impact of this intervention on other areas of child development.