Advocates of corporal punishment have outlined best practices for responsible spanking.
Real-time audio recordings of children being spanked found that parents fail to follow the guidelines, said psychologist George Holden, who is lead author on the study and a parenting and child development expert at Southern Methodist University, Dallas.
The audio interactions showed that parents were not always calm, as the guidelines recommend, but instead were often angry when they spanked or hit their child; they didn't spank as a last resort; and they gave spankings for minor infractions, not just serious misbehaviour.
"From the audio, we heard parents hitting their children for the most extraordinarily mundane offenses, typically violations of social conventions," Holden said.
"Also, corporal punishment wasn't being used as a last resort. On average, parents hit or spanked just half a minute after the conflict began," Holden added.
Parents who used corporal punishment in the audio commonly violated three of the six "use" guidelines the researchers examined: Spank infrequently, use it only for serious misbehaviour, and only as a last resort.
"The recordings show that most parents responded either impulsively or emotionally, rather than being intentional with their discipline," said Holden.
The recordings captured parent and child interactions in 33 families over the course of four to six evenings.
Parents volunteered to wear the recorders. The recordings captured 41 instances of corporal punishment, mainly during everyday activities such as fixing supper and bathing kids.
More than 80 per cent of the moms were married and had completed more education than the general population. About 60 per cent were white and worked outside the home, and their children averaged just shy of 4 years old.
In 90 per cent of the incidents, noncompliance was the immediate cause, such as sucking fingers, eating improperly, getting out of a chair, and going outside without permission.
In 49 per cent of the incidents, the parent sounded angry prior to spanking or hitting. On average, less than 30 seconds elapsed from the time when parents initiated nonviolent discipline to when they used corporal punishment.
In 30 of the 41 incidents, kids misbehaved again within 10 minutes of being hit or spanked. The youngest kid hit was 7 months old. One mother hit her kid 11 times in a row.
Researchers noted that rate of corporal punishment exceeded estimates in other studies, which relied on parents self-reporting.
Those studies found that American parents of a 2-year-old typically report they spank or slap about 18 times a year.
"The average rate we observed using the real-time audio equates to an alarming 18 times a week," said Holden.