From birth to adulthood, human proportions change several times. This results in special features for children with regard to risk of injury, movement sequences and temperature regulation.
In the first years of life, the growth of a person is greatest. Not all body parts grow at the same time, so that in some stages of development seemingly inharmonious body proportions come. Particularly noticeable in the first two years of life is the big head. The size of the head is the reason why a human baby can not even raise it and is therefore completely helpless after birth – unlike most mammals.
The shape of the head develops in the first year of life, the size results on the one hand from the initially above-average brain growth of the child. Evolutionary biology, the big head is an advantage, but he uses the childish scheme, which increases the care of adults.
Characteristic features and a big head
In children, the head is disproportionately large, the forehead region is characterized very pronounced, the big eyes, nose and mouth sit relatively far in the direction of the chin. The Austrian zoologist Konrad Lorenz coined the term child schema for these characteristics. The characteristic proportions and facial features give the parents and other adults protection and neediness. While caring and protective behaviors are pronounced, aggression is thereby mitigated. A baby’s brain grows fastest. Because of this, the head appears large compared to the rest of the body. In relation to the other proportions, there is an unfavorable relationship between volume and surface – this is the reason why why babies cool down so fast and why newborn babies should wear a hat in their first days of life. Due to the size of the head and the generally weaker muscles, the risk of injury and concussion increases. This is one of the reasons why the head should always be specially protected in children: through child seats in the car, which must stand in baby’s direction of travel or why later children should always wear a bicycle helmet.
If the head is unusually large, then the pediatrician will first look at the family characteristics. Mostly a big head is genetically predisposed. In very rare cases, a hydrocephalus may be present. This is caused by an excess of brain fluid, the so-called cerebrospinal fluid.
Development of body proportions
At the end of the first year of life, the growth in length slows down and the child gains weight, muscle and fat mass grow. Now the legs and, above all, the arms appear relatively short. At the same time, the skeleton stabilizes and body control improves. The child is now able to walk.
Due to the proportions in childhood, the surface is large compared to the body volume. For this reason, children cool easily. This is even more true the smaller they are. With increasing age, the body proportions are similar to those of an adult. If the ratio between head and body is between 1 and 5 at 2 to 5 years, primary school children already have a ratio of 1: 6, and in adults the ratio of head to body is 1: 7.
Growth spurts – Proportions during puberty
At the age of about eleven to fourteen years, the so-called second change of form takes place. During this time, one last major growth spurt takes place in which the child’s body transforms into that of an adult. This boost takes place in boys around the age of 15, girls are on average two years earlier. The growth takes place partly very demarcated. For example, legs suddenly grow while the rest of the body does not change, or hands and feet thrust through. As a result, the young people feel physically uncomfortable, the self-esteem suffers, the movements seem awkward and bumpy. In extreme cases even gross motor skills suffer. In the harmonization phase, which takes place subsequently,
In harmonic body proportions such as large heads or unusually short extremities are only rarely caused by illness. They usually balance each other over time. Due to the regular check-ups at the pediatrician, serious divergences can be detected quickly and the cause can be diagnosed.