Simacek, J. J., Riegelman, A., Gunderson, J., Worthley, E., Dimian, A. F., Chaxiong, P., Wolff, J. J. (2025). Examining behavioral interventions for infancy and early toddlerhood: A systematic review of intervention effects, parameters, and participants. Journal of Autism and Developmental Disorders. https://doi.org/10.1007/s10803-025-06804-0

 

Reviewed by: Sindhu Cherukupalli, MA, & Robert H. LaRue, PhD, BCBA-D
Graduate School of Applied and Professional Psychology, Rutgers University

Why research this topic?

Research Synopses - Psuchological, Educational and Therapeutic InterventionsRecent medical advancements have allowed practitioners to identify biomarkers and other indicators that aid in the early identification of developmental disabilities, such as autism spectrum disorder (ASD), cerebral palsy, fetal alcohol syndrome, and fragile X syndrome. Identifying children at risk of developing these disorders allows practitioners to initiate intervention in infancy before the onset of symptoms (Grzadzinski et al., 2021a, 2021b). Neural plasticity is at its highest during infancy and early childhood, providing an opportunity for interventions to produce long-lasting and substantial effects on development (Fox et al., 2010; Webb et al., 2015). Research shows that the greatest potential for improved developmental outcomes occurs when intervention is introduced as early as possible. Researchers have also suggested that proactive intervention produces greater effects than those implemented after the symptoms have begun. With earlier detection of developmental disabilities, practitioners can design targeted interventions that increase the likelihood of producing positive developmental changes. This approach is aligned with the concept of precision medicine, in which the specific mechanisms and dimensions of interventions (e.g., timing, intensity, dosage, delivery model) are tailored to the unique needs of each individual.

What did the researchers do?

In the current investigation, the researchers conducted a systematic review of the literature to evaluate the effectiveness of behavioral interventions targeting infants and toddlers during the first two years of life. The review was focused on interventions based on operant learning principles to improve long-term developmental outcomes, including social communication, motor skills, and functional play. The researchers used a variety of databases to identify empirically sound studies (i.e., APA PsycINFO, Ovid Medline, CINAHL Ultimate). The review identified 69 studies with 1,735 participants aged 1 to 23 months.

Approximately 59% of participants in the identified studies were neurotypical. About 18% of participants had a clinical diagnosis (e.g., autism spectrum disorder), while 23% were at an elevated risk for developmental disabilities. From these studies, the researchers coded the intervention characteristics/parameters (e.g., the amount of intervention, total intervention duration, and setting where treatment occurred), participant demographics, and their outcomes.

The researchers then used the coded data to report on the three main research questions:

  1. What effect did behavioral interventions have on social communication, interaction with the environment, and motor/functional play skills in infants in the first two years of life?
  2. What were the parameters/aspects of the interventions that contributed to effectiveness?
  3. What were the participant demographics, and were participants from underrepresented backgrounds included?

What did the researchers find?

The review provided several important insights regarding the characteristics and effects of behavioral interventions in infants and toddlers. Most studies included infants with intervention onset within the first year. These first-year studies were more likely to be implemented in lab-based settings and focused on fewer/less complex infant skills. For the first year, interventions primarily focused on increasing vocalization (e.g., imitation or matched responding). The review indicated that contingent caregiver responses (e.g., imitating infant vocalizations) were highly effective for increasing vocalizations and social engagement. While there were comparatively fewer studies focusing on motor skills and functional play in the first year of life, researchers noted that operant procedures (i.e., contingent reinforcement) were effective for increasing motor behaviors, such as head elevation during “tummy time” and kicking. Studies involving participants in the first year of life tended to be shorter in overall duration and have shorter session lengths.

For toddlers in their second year, intervention targets were more varied and included targeted infant behaviors, such as gestures, joint attention, functional play, and social communication. Second-year studies were more likely to include children with an identified disability and involved evaluations of the efficacy of an intervention on child and parent outcomes. These evaluations often involved manualized interventions intended to produce clinically relevant outcomes. Second-year studies were more likely to be longer-term (five months or longer), involve more complex/comprehensive interventions, and included children with or at higher likelihood for developmental disabilities. Interventions implemented in the second year were also more likely to be implemented in clinical or home-based settings and implemented by parents (rather than in lab settings).

The majority of the participants in the review were white (87%), with comparatively less representation from diverse ethnic populations. The researchers also found that many important demographic variables, such as socioeconomic status, family structure, and geographic location, were inconsistently reported.

What are the strengths and limitations of the study?

The current review has several strengths. The study provides a systematic review of the existing literature on the effectiveness of behavioral interventions in the early stages of life for neurotypical individuals. This is important because, as noted by the researchers, intervening early is beneficial in improving developmental trajectories. The review also provides sufficient evidence that using behavioral interventions in the first two years of life can have positive outcomes on infant vocalizations and functional play skills. The review also highlights gaps in the literature and provides direction for future research.

However, the current review is not without limitations. First, the experimental designs used in the studies included in this review were heterogeneous in nature, making it difficult to synthesize the information. In other words, synthesizing the findings across randomized controlled trials (RCT), single-case designs, and quasi-experimental designs can be a challenge and can impact the ability to draw definitive conclusions. Additionally, the researchers noted a lack of information on participant demographics in some of the studies, which impacts the ability to determine whether the results are generalizable to a larger population. Due to this lack of reporting, researchers could not determine which interventions were most suited for individual participants.

What do the results mean?

Behavioral interventions based on the principles of operant learning and reinforcement are effective in increasing infant vocalizations and functional/motor skills when implemented across the first two years of life. These interventions have the potential to positively alter the developmental trajectory of young children. The results indicate that more research is needed to determine the parameters of interventions that contribute to their effectiveness. They also indicate the necessity of ensuring that intervention dosages and participant demographics are adequately reported for results to be appropriately analyzed and generalized to the population.

References

Fox, S. E., Levitt, P., & Nelson, C. A., III. (2010). How the timing and quality of early experiences influence the development of brain architecture. Child Development, 81, 28-40.

Grzadzinski, R., Amso, D., Landa, R., Watson, L., Guralnick, M., Zwaigenbaum, L., Deák, G., Estes, A., Brian, J., Bath, K., Elison, J., & Piven, J. (2021a). Pre-symptomatic intervention for autism spectrum disorder (ASD): Defining a research agenda. Journal of Neurodevelopmental Disorders, 13, 1-23.

Grzadzinski, R., Nowell, S., Crais, E., Baranek, G., Turner-Brown, L., & Watson, L. (2021b). Parent responsiveness mediates the association between hyporeactivity at age 1 year and communication at age 2 years in children at elevated likelihood of ASD. Autism Research, 14, 2027–2037.

Webb, A. R., Heller, H. T., Benson, C. B., & Lahav, A. (2015). Mother’s voice and heartbeat sounds elicit auditory plasticity in the human brain before full gestation. Proceedings of the National Academy of Sciences, 112, 3152–3157.

Reference for this article:

Cherukupalli, S., & LaRue, R. H. (2026). Research Synopsis: Examining behavioral interventions for infancy and early toddlerhood: A systematic review of intervention effects, parameters, and participants. Science in Autism Treatment, 23(2).

Related Research Synopses

Related ASAT Articles:

Related ASAT Reviews:

 

#BabiesAndToddlers #BehaviorAnalysts #EIProviders #Researchers

 

Print Friendly, PDF & Email