Why does Latin America not “lisp” consonants, having learned its Spanish from Spain?

Question

I am referring to the sounds made by the letters ⟨z⟩ and the soft ⟨c⟩ the way they’re said in Spain, like in the Spanish words *zorro* and *cena*. (This is the unvoiced dental fricative sound heard at the start of the English words *thin, thaw, thank, thirty,* and *thigh*, so /θ/ using the International Phonetic Alphabet.)Latin America learned Spanish from Spain, so why does American Spanish not pronounce those consonants the same way they say them in Spain, having originally learned Spanish from people from Spain? 1. Did Latin America somehow decide at some point to start pronouncing ⟨z⟩, ⟨c⟩, and ⟨s⟩ all the same way? 2. Or did Spain begin speaking that way after Latin America was already speaking Spanish? Which one changed how those sounds are said, Spain or America?

Answer 1

It's an interesting and complex question. The main theory about this, that has some good evidence, is that the majority of people who moved to and enacted colonization in what is now Latin America came from a pretty concentrated geographical area in Spain, primarily the Canary Islands and various parts of Andalusia, where the dental fricative sound or "ceceo" is used a lot more lightly and was less articulated during the time of early colonization, especially when compared to the Castilla region, which was the official center of the Spanish Empire. This was especially true in Huelva and Sevilla, where many colonizers were born. So, the language continued to evolve from an already less "lispy" version of Spanish and in most cases, the ceceo/dental fricative that is still prevalent and thought of as the "official pronunciation" in Castilian Spanish was largely lost over time.

Hope that helps!