入鄉隨俗，還是把各地的Spanking法查一下吧

多說也無益

Spanking Laws

State by State — United States statutes as they pertaining to spanking and child abuse.

As a parent I am shocked to hear that parents are going to jail for spanking their child. This notion that "we never spank a child" is just ridiculous. There are times whem a spanking is exactly what is called for. Too bad some parents spank first and ask questions later. Unfortunately, it is illegal to spank your child in some states. So, know the law in your state... or face the consequences.

Texas

Abuse does not include reasonable discipline by a parent/guardian/managing or possessory conservator if child not exposed to substantial risk of harm. Family Code § 261.001. [Civil Code] Parent/stepparent/person standing in loco parentis to child is justified to use non-deadly force against a child under 18 when and to degree the actor reasonably believes necessary to discipline, or safeguard or promote child's welfare. Penal § 9.61. [Criminal Code]

California

Law not intended to prohibit the use of reasonable methods of parental discipline, or to prescribe a particular method of parenting. Serious physical harm does not include reasonable and age-appropriate spanking to the buttocks where there is no evidence of serious physical injury.
Welfare and Institutions Code § 300. [Civil Code]

Abuse includes unlawful corporal punishment or injury.
Penal Code § 11165.6. [Criminal Code]

"Unlawful corporal punishment or injury" is any person willfully inflicting upon a child any cruel or inhuman corporal punishment or injury resulting in a traumatic condition.
Penal Code § 11165.4. [Criminal Code]

其他州大家自己去查吧： http://kidjacked.com/legal/spanking_law.asp