A large percentage of parents of small children have a surprisingly low knowledge of child development, according to a recent study.

According to HealthDay News, the study discovered that one-third of parents of babies have little knowledge of basic concepts about what their children should know or how they should act.

For example, the study revealed that many parents don’t know that 1-year-olds can’t tell the difference between right and wrong, and often don’t cooperate or share when playing with other children.

Lead author Dr. Heather Paradis, a pediatric fellow at the University of Rochester Medical Center, in New York, said the results are surprising because the parents who took part in the survey had young children.

“They were watching or had just watched their kids go through this development, and they were probably the most knowledgeable of anybody,” Paradis said.

The study surveyed parents—98.6 percent of whom were mothers—of more than 10,000 9-month old babies, asking 11 questions designed to test their knowledge of a baby’s development. The parents were also asked about their interactions with their children and watched videotapes of how the parents taught new things to their kids, HealthDay said.

One-third of those surveyed incorrectly answered four or more of the questions. Even when the researchers adjusted the statistics to account for such factors as education levels and income, those parents were still less likely to enjoy “healthy interactions” with their children, HealthDay reported.

A lack of proper understanding of a child’s development can cause assorted problems, Paradis said.

“A mom could misinterpret a child’s normal curiosity as intentionally being defiant, and could respond with harsh discipline, withdrawal of affection and repetition of that pattern over time,” she added. “That could hinder the child’s potential for full growth and development.”

One solution, Paradis said, is for pediatricians to take a more active role in educating new parents. “By improving knowledge of child development among all parents, not just those who are at highest risk, there’s an opportunity to enhance parent-child interaction,” she said. “It can ultimately lead to better parenting.”

The findings were recently presented Sunday at the Pediatric Academic Societies’ meeting in Honolulu.