Why do kindergarten children have more synapses than at birth and than their teachers?

• A. Genetic mutation.
• B. Increased myelination.
• C. Decline in neuron numbers.
• D. Synaptogenesis and lack of pruning.

Answer: (D)

The key idea is that early brain development involves a burst of synapse formation followed by pruning to refine those connections. After birth, the brain rapidly creates many synapses in response to new experiences and learning. Kindergarten children are in this peak period where synaptogenesis is dominant, so they have a high number of connections. As people grow and gain experience, pruning trims away extra synapses to streamline networks, so teachers—older and more experienced—tend to have fewer synapses than young children. The other options don’t fit because genetic mutation isn’t the normal driver of this typical developmental surge, increased myelination changes signaling speed rather than the sheer number of synapses, and a decline in neuron numbers would reduce synapses instead of increasing them.