Scientists have long known that certain motor milestones, such as crawling or walking, can help parents and clinicians track early childhood development. Now, it turns out that those milestones might be tied to a child's future development, according to the study, which was published in the journal Pediatrics
"Our findings are consistent with those of longitudinal studies performed a few decades ago, showing that the age a child achieved major milestones of standing or walking were predictors of later child performance in memory," said Akhgar Ghassabian, a postdoctoral fellow at the National Institutes of Health and lead author of the study.
"Given advances in prenatal care, the lifestyle of contemporary women and children, advances in pediatric medicine and early interventions, we undertook our study to determine if the timing of major milestones correlated with later development in a contemporary United States sample of children," she added. "This is a promising lead, but we need more studies to see if this will actually pan out."
The researchers analyzed milestone reports collected on 599 children born between 2008 and 2010 in upstate New York as part of the Upstate KIDS Study
, a project by the National Institutes of Health in partnership with the New York State Department of Health and the University at Albany.
The reports, which were recorded by the children's mothers, tracked gross motor development at 4, 8, 12, 18 and 24 months.
Each mother wrote down when her child sat up without support for the first time (which usually happens around 6 months
), crawled for the first time (usually around 9 months) and stood and walked for the first time with and without assistance. Most children learn to walk at about 18 months
"In this study, parents completed an easy-to-administer assessment on their children's progress, which served as a useful indicator of later development," Ghassabian said.
From the results, researchers found an association between the age at which babies stood with assistance for the first time and how they performed on cognitive tests at around age 4.
Most of the babies stood up with assistance by around 9 months. Those who didn't reach that milestone until 11 months, however, had significantly lower scores than average on cognitive and adaptive tests at around age 4.
Meanwhile, the babies who mastered standing with assistance earlier than average were more likely to achieve higher test scores and to master other skills, such as learning to feed themselves, before age 4.
The twin twist
Yet, the researchers noticed very different results in twins. It turned out that if a baby in the study had a twin, the milestones of two twins during infancy could not necessarily be linked to their achievements later in life.
"For twins, key predictors of later development, such as gestational age and birth weight, overshadow the potential predictive role of milestones in infancy," Ghassabian explained.
The researchers concluded that, at least for non-twins, there might be an association between motor milestones and cognitive abilities later in life. Motor skills can foster connections between various circuits in the brain.
For instance, the brain's basal ganglia
, which is associated with motor control, seems to interact closely with other parts of the brain that regulate cognitive function.
"Being able to identify any delay in a child's development early is important. Intervening early can greatly improve a child's developmental outcomes," Ghassabian said. "Also, identification of any deviation from normal development and, subsequently, diagnosis is a stressful process for parents. Parents are very aware of their children's developmental stages. We showed that parents are very helpful in identifying developmental delays in children."
But not everyone agrees.
"By and large, the study is only exploratory and descriptive," said Robert Pianta, dean of the University of Virginia's Curry School of Education, who was not involved in the study.
"No one -- parents or pediatricians -- should take these results as a sign that certain gross motor milestones predict how well a child will perform on school readiness tests," he added. "Of course it's very likely that motor development is indeed a key part of young children's growing set of skills, but much more research is needed to establish the links."
Scott Johnson, professor of psychology at the University of California, Los Angeles, who was not involved the study, also said that there are still key questions regarding motor milestones and cognitive skills that remain to be determined.
"The present article is important in demonstrating the possible links but doesn't specify what the developmental mechanisms might be," he said. "That would require more studies."
So, what does this mean for parents? Instead of closely monitoring your child's development with motor milestones, Doris Bergen, distinguished professor emerita of educational psychology at Miami University in Ohio, suggests an alternative.
"Parents do not need to 'monitor' children's development in that way, but they should be sure to give children many opportunities for gaining enactive cognition," said Bergen, who was not involved in the study.
is the idea that cognition can develop through children having physical interactions with their environments.
"When you engage in activity that requires you to use your body and muscles, you learn through that activity. If a baby is manipulating objects or trying to climb stairs, the baby is cognitively, as well as motorically, engaged. When you learned to ice skate, you did not just learn muscle skills but a cognitive understanding about ice, temperature, balance, spatial features, interaction with objects and people. So enactive cognition is the first kind a baby has, but we have it throughout life," Bergen explained.
"One concern presently is that often children today are too static, with less outdoor play and more technology-augmented play," she said, "and this study at least suggests that parents should be sure that their children's motor development is as much of a concern as their cognitive development."
Thus, one small step for a baby is still a giant leap for childhood development.