(CNN) -- Tara grew up thinking that spankings or a smack on the arm were normal punishments for breaking a
plate or playing her music too loudly. She never knew what would set her father off, and her mother never
intervened, so she did her best to avoid him, walking on eggshells whenever he was around.

"It wasn't until I grew older and was out from under my parents' roof that I learned it wasn't the norm," said Tara, a
34-year-old public relations consultant in Phoenix. She asked that her last name not be used because she no
longer talks to her father and fears drawing his attention.

"I think my father truly didn't care enough to 'teach' me how to be, but instead would try to knock undesirable
behaviors out of me."

As she watched the YouTube video last week of a Texas judge beating his daughter, Tara's mind wandered to an
afternoon in her senior year of high school more than a decade ago, when her father's idea of discipline turned into

He burst into her room, yelling and swearing. Another teacher at Tara's East Tennessee high school, where her
father worked, had told him that students were saying that she had kissed a black boy. He cursed at his daughter
as he slapped and punched her all over, his clunky school ring pounding her skin like a brass knuckle.

"Seeing that girl made me think, wow, that's what I lived through," Tara said. "I saw so much of myself in it, it made
me shudder to think back on it."

Among psychologists, Tara's flashback is considered a symptom of post-traumatic stress disorder from years of
physical and emotional abuse, and it's just one of many potential lasting effects when discipline crosses the line
into abuse.

Overheard on CNN.com: Family court judge should not beat child

Parents have long been using spankings, swattings or whippings to "correct" a child's behavior. But as social norms
evolve and more research surfaces in support of alternatives, the line between "corporal punishment" and child
abuse is becoming increasingly blurry.

Judge leaves post after taped beating 'SuperNanny': Beating was child abuse

The controversy came to the fore last week, when the YouTube video of the judge repeatedly hitting his teen
daughter went viral. The video is a stark depiction of a wailing girl in a dark room begging her father to stop
whipping her with a belt, and it prompted widespread outrage.

The daughter, now 23, said she posted the video to make a point to her father, who she felt was in denial about the
way he treated her years ago. William Adams, a court-at-law judge in Aransas County, Texas, faces a judicial
conduct investigation because of the incident. He will not face criminal charges because the statute of limitations on
a charge of felony injury to a child has expired.

Spankings under the guise of discipline are still commonplace in the United States. A fair share of reaction to the
YouTube video contained the sentiment that physical discipline reinforces the notion of consequences for actions.
"Parents waste a lot of words on kids. Kids want what they want. A lot of times, a good spank to the bottom
communicates the words that you have to communicate," said Chad Smith, a personal trainer from Hagerstown,
Maryland, whose mother took a belt to him whenever he got out of line.

"That being said, there's a difference between discipline and abuse. People tend to think of abuse when they think
of manual correction, but there's a line there. With that video, what got to me was her age, and the fact it went on
for so long."

For Tara, who endured prolonged or severe instances of violence under the guise of discipline, the video took her
breath away. It also forced her to  reflect upon how her experiences with "physical correction" had altered the
course of her life.

"I suffer from anxiety and never really feel 'safe.' I worry a lot about the most trivial things, and I truly believe this is
a result of me never feeling safe in my own home," she said. "Luckily, I have a good therapist and an amazing
husband who doesn't have the same baggage as me."

She is lucky, because she, and many like her, might seek the familiarity of an emotionally volatile relationship or
subject their own children to similar treatment.

She grappled with the prospect of having children, fearing that she might treat them the same way her father
treated her.

"I can't say I never gave them a pop on the bottom in the beginning, but never to the same extent as my dad," she
said. "Counseling has helped me understand that when I get mad with them, it's up to me to stop and really think
and put things in perspective. Most of the time, it's based on things going on in my world that stress me out."
Just as crucial to seeking treatment was learning to forgive her parents -- still a work in progress, she said. It's not
about excusing or absolving them of what they did, but understanding what motivated the behavior and empathizing.
"He was beaten as a child as well, and I am sure this kind of behavior with his own children was a learned behavior,
but through education and understanding, I just can't imagine that an adult couldn't make better decisions to
change and make the lives of their own children better by doing the hard work to improve their own parenting
shortcomings. "

Numerous studies have been conducted in recent years to support the theory that physical forms of discipline do
more harm than good, said George Holden, a professor of psychology at Southern Methodist University, who has
published five books on parenting and child development.

"The line between discipline and abuse is a gray area, and it's also sort of fluid because a parent might begin with
using what they consider appropriate or reasonable discipline. But in the course of seconds, it can easily escalate
based on a child's reaction or a parent's rage," he said. "It's easy to inadvertently cross the line, wherever it is."

Hurting your child can also harm the parent-child relationship by infusing it with pain and negative emotions, he
said. Children who are spanked are also more likely to be aggressive toward others because they don't know any
other way to behave.

When physical force is combined with derogatory or emotionally abusive comments, like the ones in the YouTube
video, the damage can be even greater, said psychologist Gregory Jantz, author of "When Your Teenager
Becomes the Stranger in Your House."

"You're degrading their personhood, attacking them as a person, their character, their worth and value," he said.
"Combine that with the anger and the hitting, that's what we call violence, and that's about power and control: one
person, through physical force, exerting power and control over the other."

Studies have also found an elevated risk of heart disease related to childhood trauma, said psychologist Melanie
Greenberg, who studies the effects of stress and trauma on the mind and body.

"There is evidence that child abuse changes brain function in areas related to processing threat. Chronic stress
can lead to imbalance of the autonomic nervous system," she said, referencing the Adverse Childhood Experiences
Study, a collaboration between the Centers for Disease Control and Prevention and Kaiser Permanente.
Such an imbalance can distort one's fight-or-flight perception, causing a tendency to overreact or magnify
perceived threats, she said.

Denise Parker knows it firsthand. She recalls the time she bought a bottle of wine with a pretty label for a former
boyfriend that turned out to taste awful. She was immediately paralyzed with fear, expecting that he might yell at her
or break up with her.

Years of counseling helped her realize that it was her father's voice in her head, telling her that she was stupid and
not good enough, just like he had when she was younger.

"He thought it was discipline. It could be that we did something wrong, we spilled something or broke a dish, but to
me, the punishment never matched what happened," she said. "I think all the anger he had inside would come out
in those moments. Anything could be under his guise of needing to punish us for something."

Other patterns have been harder to break, she said. Her husband, who was beaten as a child, was verbally
abusive until a few years ago, when she started to go to counseling and learned to assert herself.

"I was attracted to the unfinished business with my dad, the level of comfort with someone who also had so many
issues, because I knew how to manage them," she said. "I believed if he loved me enough, he would go to
counseling and be willing to change.

He never did, though, she said. She and her husband have a daughter and a decent life, but she doesn't see it
lasting forever, she said.

"His behavior is nothing like my dad's, there's no abuse and he doesn't hit her, but he doesn't give her enough
attention," she said. "I try to manage that relationship best way I can by creating a life for her that's very different
from the childhood I had."

Keeping anger out of the situation is the key to effectively disciplining a child, said clinical psychologist Marla
Deibler, who performs court-ordered evaluations for children and families in New Jersey's family court system.

"You punish kids because you don't want them to do it again, but physical force doesn't show them what to do
instead, and it doesn't educate them on a better way to cope or problem solve," she said. "It's crucial that they
understand why they're being punished and that the punishment is reinforced with positive emotions."

Jonathan Holliday agrees that it's all in the approach. He credits his childhood whippings with teaching him the
difference between right and wrong and instilling in him respect for his parents.

"After I'd get a spanking, I would think the next time before I did something," the 21-year-old University of Arkansas
student said.

His mother disciplined her son and daughter, he said. She always explained to them what they had done to prompt
her use of the belt, he said. When the whippings were over, she would leave the room for a bit and return to give
them a hug and reiterate the lesson she wanted them to learn, he said.

"The main thing is she never whooped us without reason and she always backed it up with love," he said. "I could
tell she hated doing it, but she never did it out of anger. She did it out of love and the fact she was worried about
our actions. She didn't do it because she was angry, and she never cursed and she always had an explanation for