Department of Design Strategy, Faculty of Design
Physiological Anthropology Research Center (Resilience Design Group)
Associate Professor Fuji Tomoaki
Chimpanzees, the closest relative of humans, take between four and five years to raise one of their offspring before attempting to have more, and childrearing among chimpanzees is the sole duty of the mother. In contrast, humans spend approximately twenty years raising multiple children simultaneously. And among humans, both mother and father as well as grandparents are involved in the childrearing process.
Humans, who had to move out into the dangerous grassy plains due to climate changes and shrinking rainforest areas, developed large brains which gave us highly advanced cognitive abilities. This allowed us to avoid extinction and prosper, but it also meant that it would take approximately twenty years to raise a human child due to the immature state of the brain and body at birth.
Since it takes so long to raise a child, the number of children that can be raised during the course of a single lifetime is reduced. We humans have subsequent children before the first child to be born has reached adulthood; therefore, we preserve our species by simultaneously raising multiple children. This would be difficult to accomplish if only the mother were responsible for raising multiple children. Hence, human fathers and grandparents also take part in the child raising process. The human strategy is for everyone to raise larger numbers of children that require a great deal of care. Human children are raised by everyone.
However, in present-day Japan the nuclear family is becoming more and more prevalent and as a result it is becoming impossible for children to be raised by “everyone”, as is the natural tendency. Under such circumstances, mothers - who are unable to shirk their maternal responsibilities due to the fact that they breastfeed - have no choice but to take on a great deal of the burden of childrearing.
The most effective type of support that can be provided to mothers who are worried about childrearing is social and human support. This is only natural when one considers that the original human child-rearing style was for children to be raised by everyone. However, as there are no grandparents in the homes of nuclear families upon whom mothers can rely and as we have only superficial relationships with our neighbors in modern society, it is also necessary to depend upon material aides such as childcare supplies.
Therefore, in our laboratory we focused on “putting babies to sleep,” which is one of the major worries that many mothers have. We developed the electric swinging crib to help mothers to rearing their babies , (Figures 1 and 2). This crib automatically begins to swing the baby upon detection of the baby’s crying. The swing distance is approximately 10 cm. At first, the swings are at a slightly higher speed, but then they slow to a speed that is the same as a mother’s heartbeat. The swinging is set to stop after 15 minutes in the interests of safety. In performance evaluation experiments , it was shown that this crib was effective for approximately 80% of babies (Figures 3 and 4). Many experiments were conducted at a variety of swinging speeds and swing distances, but the rhythm at which babies felt was most comfortable was perfectly matched to the rhythm of a mother’s heartbeat. We were greatly moved upon observing these data.
We often hear provocative statements such as “it’s only natural that a mother has to work that hard” and “maybe she isn’t qualified to be a mother.” But human children are supposed to be raised by everyone. We shouldn’t be pressing upon individual mothers the sole responsibility of childrearing. That is why we are working to create a society in which everyone helps each other and children are raised by everyone.
 Fuji Tomoaki, Tateishi Kenji. Design of the Electric Swinging Crib for Childcare and Verification of the Baby Calming Responses. Journal of Japan Society for Design Engineering, 52, 4, pp. 217-228, 2017
 Fuji Tomoaki. Development of the Electric Swinging Crib for Childcare: Infant Calming Responses to Swinging Stimuli. Journal of Japan Society for Design Engineering, 49, 9, pp. 492-497, 2014
Swing-type crib Suima（http://suima.jp）