Toddler vs. Newborn: Physical and Neurological Growth

Toddler Appearance vs. Newborn Appearance

A two-year-old is very different from a newborn baby, as the biological changes that occur in the first two years of a child's life are fast and spectacular. A newborn is about 51cm and weighs less than 4 kg. At two years, most children weigh over 13 kg and measure between 81 and 91cm, with boys generally having greater weight and height than girls. Moreover, the newborn is disproportionate, with a large head (one-quarter of body length). At two years, this proportion changes significantly.

Brain Maturation Indicators in Child Development

The maturation of the brain is responsible for increasing the regularization of sleep and wake rhythms in the child. It also drives changes in the child's ability to respond to and control their responses to the environment. This highlights the crucial relationship between neurological maturation and behavioral change.

Principles of Motor Development in Humans

There are several key principles of motor development:

• Proximodistal: The human body develops from the center outwards.
• Cephalocaudal: Human development progresses from head to foot. Babies have disproportionately large heads because that part of the body is more developed initially.
• Dynamical Systems: Individual motor skills develop when children are motivated to perform a task and possess sufficient physical resources.

Reflexes in Children: What Are They and What Do They Do?

Reflexes are involuntary responses to specific stimuli. Some are essential for sustaining life, others disappear completely in the months following birth, and some form the basis for later voluntary movements. All are important signs of neurological health and behavioral competence.

• Sucking Reflex: This is one of the most important reflexes for a newborn, enabling them to feed by sucking on the mother's nipple or a bottle nipple. After a few months, sucking becomes a mechanism for exploring objects and their properties.
• Walking/Swimming Reflexes: If you hold a baby upright on a hard surface, they will initiate walking movements. Similarly, if you hold a baby on their stomach in water, they will make synchronized arm and leg movements. Both the walking (2-3 months) and swimming (at 6 months) reflexes disappear within a few months after birth. The function of these reflexes is not entirely clear, but they are presumably remnants of our evolutionary past.