Given this anatomical closeness of amygdala and hypothalamus, with both involved in rage/anger/sexual response isn't it reasonable to think that one feeling could infuse another?
Isn't it reasonable to think a severe spanking could enrage a child, whatever the reason, and that rage carry over into other feelings, especially if he/she is a frequent recipient of such violence?
If the reason is to change behavior, corporal punishment may work in the short term, but what does it actually teach the child? It certainly doesn't teach him/her that thinking is a desirable trait, just physical coerction is. A thinking parent would control their reaction and restrain a small child and deprive an older child,for instance. Both take more effort and discipline on the part of the parent. Not being perfect parents, we may not always achieve this discipline within ourselves, because, indeed, it is not easy! But parenting is not about taking the easy way out and takes an enormous amount of discipline and isn't this the modeling we are suppose to show our child?