Alma 27

Mormon tells us -

"...that the Amalekites, because of their loss, were exceedingly angry. And when they saw that they could not seek revenge from the Nephites, they began to stir up the people in anger against their brethren, the people of Anti-Nephi-Lehi; therefore they began again to destroy them."  (Alma 27:2)

Where the converted Lamanites began to experience and show brotherly love, there were many that chose not God and His ways were angry and began to destroy.  Seems again to be much like today.