Not an expert (but a background in neurophysiology). Synaptic pruning (deleting synapses) is an important part of neural development. Here's a ref [1] with a c

Not an expert (but a background in neurophysiology). Synaptic pruning (deleting synapses) is an important part of neural development. Here's a ref [1] with a couple of paragraphs (see "Synaptogenesis" and "Synapse Pruning"). Synaptic pruning seems widespread in mammalian neurodevelopment. I wouldn't be surprised to find it's involved in some ultrastructural neural aspects of intelligence. [1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3722610/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3722610/