Emily Wood

This study compared the language, cognition, and social-emotional development between twins and their younger singleton siblings at the ages 2, 3, 4, and 7 years. Data were collected 1996–2004 from 851 sibling trios from the Twins Early Development Study (TEDS; 50.2% female; 93.2% White British). Distributions were comparable between twins and singletons across domains, indicative of mean rather than variance discrepancies. Twins performed worse than singletons in language, cognition, and social-emotional development across ages, with small to moderate effect sizes (d = 0.17–0.62). An exception was language at age 7 years, when twins exceeded their singleton siblings (d = −0.35). Overall, twins and their singleton siblings differed in development across domains and their differences in language reversed during childhood. This study compared the language, cognition, and social-emotional development of twins and single-born children (singletons) at ages 2, 3, 4 and 7 years. Data were collected between 1996 and 2004 from 851 twin pairs and their younger singleton siblings, as part of the Twins Early Development Study (TEDS). Twins scored lower than singletons on tests of language, cognition, and social-emotional development across all ages. An exception was language at age 7 years, when twins scored higher than singletons. Overall, the study found twins and singletons differ in their language, cognition, and social-emotional development, though their differences in language reversed during childhood.

Introduction: Nursery rhymes, which are rich in literary devices, benefit children's language learning. Less is known about the influence that nursery rhymes' messages may have on children's development. We focused on “Monday's Child,” a popular nursery rhyme that alleges children's day of the week of birth forecasts their differences in personality and physical traits. Methods: Data came from E‐Risk, a UK population representative, longitudinal cohort study of 2232 same‐sex twin children (with 93% retention). We used linear regression models to test whether the day of the week of birth predicted personality and physical traits at ages 5–18 years. Results: Being born on Monday through Saturday did not predict children's personality and physical traits as implied by the “Monday's Child” rhyme. Being born on Sunday was also not associated with children's traits across measures. These results were unchanged after covariate adjustment (i.e., children's sex, birthweight, and socioeconomic status). Conclusion: We showed that children's differences in personality and physical traits are independent of their day of the week of birth. These findings suggest that nursery rhymes' messages are unlikely to influence children's development, at least those conveyed by “Monday's Child”.

This study compared the language, cognition, and social-emotional development between twins and their younger singleton siblings at the ages 2, 3, 4, and 7 years. Data came from 851 sibling trios from the Twins Early Development Study (TEDS), a family cohort born in 1994-1996 in England and Wales (50.2% female; 93.2% White British). Twins performed worse than singletons in language, cognition, and social-emotional development across ages, with small to moderate effect sizes (d=0.17-0.62). An exception was language at age 7 years, when twins exceeded their singleton siblings (d=-0.35). These findings suggest that (a) twins and their singleton siblings differ in development across domains and (b) their differences in language reverse during childhood.

Nursery rhymes are rich in alliteration and vocabulary, and their benefits for children’s language and literacy have been widely studied. Less is known about the influence that nursery rhymes’ messages may have on children’s development. Here, we focused on ‘Monday’s Child’, a popular nursery rhyme which alleges that the day of the week of children’s birth forecasts their differences in physical and psychological traits. Data came from E-Risk, a UK-population representative, longitudinal cohort study of 1,116 families, whose same-sex twin children were assessed at ages 5 through to 18 years (with 93% retention). In our preregistered analyses, being born on Monday through Saturday did not predict children’s physical and psychological traits as implied by the ‘Monday’s Child’ rhyme (β = -.04 to .03; 95%CI = -0.10 to 0.09; p = .195 to .754). Being born on Sunday was also not associated with children’s traits across measures (β = -.00; 95%CI = -0.05 to 0.05; p = .945). Results were unchanged after covariate adjustment (i.e., children’s sex, birthweight, and socioeconomic status). Our findings suggest that children’s differences in physical and psychological traits are independent of the day of the week of their birth, refuting the messages from ‘Monday’s Child’ nursery rhyme.