Why is a newborn babies head bigger than an adult?

A newborn baby's head is proportionally larger than an adult's head due to the rapid growth and development of the brain during the first year of life. At birth, the brain is about 25% of its adult size, and by age two, it reaches approximately 80%. This larger head size supports the necessary space for the developing brain, while the rest of the body continues to grow at a different rate, resulting in a relatively larger head compared to the body. Additionally, the soft skull bones in infants allow for flexibility during birth and accommodate brain growth.