Final answer:
Although it was a common misconception that brain development stops after childhood, the truth is that development continues throughout life. The brain's structure becomes more complex, and processes like synaptic pruning and myelination enhance its efficiency into adolescence and beyond.
Step-by-step explanation:
Most people mistakenly believed that brain development stops after childhood. In reality, brain development is a continuous process that occurs throughout one's life. Different aspects of the brain, such as the number of folds in the cerebral cortex and processes like synaptic pruning and myelination, contribute to its increased efficiency and functionality, especially during adolescence. Lifespan theories in developmental psychology argue that development is lifelong, and both genetic and environmental factors play significant roles. It is understood that cognitive, physical, and psychosocial development does not adhere strictly to genetic determination; rather, environmental influences significantly contribute to an individual's intelligence level and development.
The understanding that there are myriad factors affecting brain development, demonstrates the complex interplay between nature and nurture in determining intelligence and other cognitive abilities. Moreover, frontal lobes continue to develop into early adulthood, not ceasing at childhood as once thought.