Influences on Achieving Motor Milestones: A Twin–Singleton Study

Genetic and Environmental Influences on Developmental Milestones and Movement: Results From the Gemini Cohort Study

“…However, it is also possible that the environment has changed since these earlier studies and that parental and societal patterns are exerting stronger effects. Twins attain their developmental milestones slightly later than do singletons, although a study comparing 2,151 twin pairs and 2,151 singletons revealed no significant differences in age when reaching five developmental milestones (turn, sit, crawl, stand, and walk) within the normal range (Brouwer, van Beijsterveldt, Bartels, Hudziakm, & Boomsma, 2006). There is no reason to suppose that the magnitude of genetic and environmental influences would differ between twins and singletons.…”

Twin–singleton influence on infant development: a national birth cohort study

“…2008). By contrast, a 0–24 months' twin–singleton comparison study did not find a difference between the gross motor development of twins and singletons (Brouwer et al . 2006).…”

Comparison of Naturally Conceived and IVF-DZ Twins in the Netherlands Twin Registry: A Developmental Study

“…In survey-2, mailed out when the twins were 2 years old, the mother was asked to report the age at which certain motor milestones were reached (turning over from back to belly (turning), sitting without support (sitting), crawling on hands and knees (crawling), standing without support (standing) and walking without support (walking)) [43, 44]. With survey-1, mothers received a memory aid to track the motor milestones.…”