What advantages might there be for infants to be born with morenerve cells (neurons) than they actually need oruse?  

Think of language, for example. When a human infant is born,he/she has to ability to learn to speak any language that humansspeak however, as the infant grows and is exposed to onepredominant language in his/her home, this becomes the languagethat the child learns to speak. The child sounds like other nativespeakers of his/her language. Later, if the person decides to takea foreign language in high school, he/she will most likely soundlike a foreign speaker when speaking the newly learned language orfor some students, learning a foreign language is a ratherdifficult task.

In later life, if a person has a cerebral vascular accident(CVA) or what people in the community call \"a stroke\", and thisperson speaks more than one language, after the CVA, she/he willmore likely be able to speak basically the first language learned.The second, third, etc. languages the person learned, willtypically be very difficult for this person.

Example: Elisita was born into a Spanish speaking family inMexico . Her parents spoke only Spanish in the home, as didElisita's siblings and other relatives. Very few of Elisita'sneighbors spoke English therefore Elisita was never exposed to thesound of English as a baby/toddler. When Elisita was two years ofage, her family migrated to Chicago, Illinois. At age five, Elisitawas enrolled in a public school where she was exposed to theEnglish language at least six hours per day. She learned to speakEnglish quite well. When Elisita was age sixty-nine, due touncontrolled high blood pressure, she suffered a cerebral vascularaccident. With some speech therapy she was able to recover a greatdeal of her Spanish language skills, but her ability to speakEnglish was impaired.