Care in a Group Setting Has Positive Effect on the Development of Young Children

For about 60 years, the prevailing view in Japan—the so-called “three-year myth”—has been that children should be raised at home by their mothers for healthy development until the age of three. However, research findings from the Tohoku University School of Medicine show that childcare in daycare centers during early childhood does not hinder children’s development and may even promote their social, motor, and problem-solving skills.

Belief in the “three-year myth” persisted, even though Japan’s Ministry of Health, Labour and Welfare insisted that it had no rational basis. Nevertheless, Japanese mothers often struggle with feelings of guilt and anxiety over their decision to place their children in daycare when they return to work. In a recent study published in Scientific Reports, a research team led by Dr. Keita Kanamori, a doctoral student, and Professor Chiharu Ota of the Institute of Developmental and Environmental Medicine found that children who entered daycare at six months of age showed better development at age three than children who were raised at home. The improvements were evident in five areas: communication, gross motor skills, fine motor skills, problem-solving ability, and personal and social skills.

How Children Might Benefit from Early Childcare

The researchers analyzed data from approximately 40,000 participants in the government-sponsored Japan Environment and Children’s Study (JECS), a large-scale birth cohort study in Japan, where parenting values differ from those in Western countries. The JECS, which took place between 2011 and 2014, followed 100,000 mother-child pairs across Japan to determine the influence of environmental factors on children’s health and development. The greatest developmental differences between these toddlers and those raised at home were evident in the areas of communication and personal-social skills. The toddlers in early childhood care also had better motor skills—that is, the ability to control and coordinate their movements. The authors speculated that this might be due to the fact that they spent more time with other children.

A key benefit of early care in a daycare center is social diversity. There, children encounter many other children of different ages and temperaments every day. This creates far more opportunities for interaction: they must share, wait, resolve conflicts, and make themselves understood. It is precisely these repeated social situations that particularly strongly promote communication skills and social competence. At home—especially with one-on-one care—this diversity of social stimuli is often significantly less prevalent.

Another important factor is linguistic stimulation. In a daycare center, children speak not only with one caregiver but with several adults and children. They hear different ways of expressing themselves, have to explain themselves more often, and learn to use language actively more quickly. This may explain why the study revealed differences particularly in the area of communication. Motor development can also be influenced by the environment. Daycare centers often offer targeted physical activities: climbing, running, crafts, or group games. These activities promote both gross motor skills (e.g., running, jumping) and fine motor skills (e.g., grasping, cutting). Additionally, children motivate each other—when one child tries something new, others often want to imitate it. This dynamic is frequently absent at home or is less pronounced.

Another key aspect is cognitive stimulation. In childcare centers, there are structured activities designed to specifically foster problem-solving skills: puzzles, games, and collaborative tasks. Children are encouraged to find solutions on their own and learn new strategies by observing other children. This “learning in a social context” is considered particularly effective in developmental psychology. However, these benefits are most evident when the care is of high quality—that is, when there are well-trained staff, small groups, and a stimulating environment. At the same time, growing up at home offers other important strengths, such as a close bond, individual attention, and often less stress due to fixed routines.

Impact on Attachment Formation and Emotional Development

Although these findings suggest that early childhood care could lead to improved development, the researchers noted that only a small percentage of children raised at home fell below standard developmental thresholds. Both home-based and childcare-based child-rearing have a variety of benefits, they say, and they hope their research dispels the myth that staying at home with the mother until age three is essential for healthy development. “Our core message is that both daycare and home-based care are viable options, and families can choose what works best for them without guilt or anxiety,” says Ota. Looking ahead, the team plans to investigate how early childhood care affects children’s development beyond the age of three, as well as its impact on attachment and emotional development.

On the one hand, the question is whether the early benefits—such as in language, motor skills, or social behavior—persist over time. It is conceivable that children who were in care early on may also find it easier to learn later in school, integrate better, or solve problems more independently. However, it is equally possible that differences will even out over time because other factors such as school, family, or social circles become more influential. A second key point is attachment development (i.e., the emotional relationship between the child and caregivers, a central theme of attachment theory). For a long time, there was concern that early childcare might weaken the bond with the mother or parents. Future studies could clarify whether this concern is justified or whether children can develop secure and stable attachments despite (or even because of) having different caregivers—and may even become more flexible in their social interactions.

Practical Implications

Closely related to this is emotional development. Researchers want to understand whether children who receive early care show differences later on, for example in:

• their coping with stress
• their ability to regulate emotions
• their self-confidence and social behavior

This could have very practical implications for the future. If it turns out that high-quality early childhood care has long-term positive effects, this could:

• encourage education systems to invest more in daycare centers
• make it easier for parents to decide to return to work sooner
• change social norms (e.g., less guilt about using childcare)

If, on the other hand, more nuanced results emerge (e.g., benefits only under certain conditions), this could lead to clearer recommendations—such as regarding optimal care quality, group size, or the duration of the adjustment period. In short: This future research will help determine how we as a society organize, evaluate, and support early childhood—and it could help replace ideologically driven debates with well-founded scientific insights.