Comprehensive Evaluation of Language, Speech, and Communication Skills in 24- to 36-Month-Old Twins and Singletons:...

Early language development forms the foundation for cognitive, social, and academic skills. This study aimed to compare the language, speech, and communication skills of twins and singleton children aged 24-36 months and to explore associations with sociodemographic, biological, and environmental factors in the Turkish population METHOD: The study was conducted with 100 children, comprising 30 twin pairs (60 children, 30 male, 30 female) and 40 singletons (23 male, 17 female), with a mean age of 33.4 ± 5.26 months. Receptive and expressive language skills were evaluated using the Test of Early Language Development-Third Edition, Turkish Version (TEDIL), parent-reported language skills were assessed with the Adapting the Language Development Survey to Turkish (DILTAR), communication skills were evaluated with the Children's Communication Checklist-2 (CCC-2), and speech development was assessed with the Ankara Articulation Test (AAT). Sociodemographic (maternal age, education), biological (birth weight, gestational age), and environmental (television viewing time) factors were analyzed through correlational analyses.

Twins exhibited significantly lower birth weights and earlier gestational age at birth compared to singletons. Twins demonstrated lower performance in TEDIL receptive language scores and AAT scores compared to singletons (p < 0.05). In the CCC-2 subscales of speech, syntax, semantics, use of context, and social relationships, twins scored significantly lower than singletons. A negative correlation was found between TEDIL receptive language scores and television viewing time across all children (r = -0.603). In twins, statistically significant correlations were observed between language-related scores and maternal age, maternal gestational age, birth weight, and maternal education (p < 0.05).

This study provided culturally grounded evidence from Turkish children and demonstrated that 24-36-month-old twins are at increased risk for delays in language, speech, and communication skills compared to singleton peers. The findings suggest that the twinness effect in early toddlerhood reflects the combined influence of biological maturity at birth (e.g., lower birth weight and earlier gestational age), sociodemographic characteristics (e.g., maternal education and age), and environmental factors (e.g., television viewing time). Rather than being attributable to a single determinant, early language and communication outcomes in twins appear to emerge from dynamic interactions between biological and environmental conditions. These results underscore the importance of early, multidimensional screening and comprehensive assessment of twins' communication development to facilitate the timely identification of potential delays. Early intervention approaches that combine speech-language therapy with enriched environmental support strategies may help mitigate developmental risk and promote optimal communication outcomes.