WT's view on corporal punishment has changed since the 1980's and the 90's:
The Bible associates such discipline, or instruction, with love. (Proverbs 13:24) Therefore, “the rod of discipline” should never be abusive—emotionally or physically.a (Proverbs 22:15; 29:15) Discipline that is rigid or harsh with no sense of love is an abuse of parental authority and can crush a child’s spirit. (Colossians 3:21)
In Bible times, the Hebrew word for “rod” meant a stick or a staff, such as the one a shepherd used to guide his sheep. (Psalm 23:4) Similarly, “the rod” of parental authority suggests loving guidance, not harsh or brutal punishment.
“The rod” refers to parental authority that must be applied lovingly to prevent children from going astray. Wielding such authority does not involve abusing the child in any way.
But parental authority—“the rod of discipline”—should never be abusive.b
Some shy away from the word “rod,” thinking that it implies some kind of child abuse. But it does not. The Hebrew word for “rod” referred to a staff, such as the one a shepherd used to guide—not assault—his sheep.a So the rod stands for discipline.