"I've worked with thousands of parents and I can tell you, without question, that screaming is the new spanking," said Amy McCready, the founder of Positive Parenting Solutions, which teaches parenting skills in classes, individual coaching sessions and an online course. "This is so the issue right now. As parents understand that it's not socially acceptable to spank children, they are at a loss for what they can do. They resort to reminding, nagging, timeout, counting 1-2-3 and quickly realize that those strategies don't work to change behavior. In the absence of tools that really work, they feel frustrated and angry and raise their voice. They feel guilty afterward, and the whole cycle begins again."

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One study that did take a look at the topic — a paper on the "psychological aggression by American parents" published in the Journal of Marriage and Family in 2003 — found that parental yelling was a near-universal occurrence. Of 991 families interviewed, in 88 percent of them a parent acknowledged shouting, screaming or yelling at the kids at least once (though it didn't specify how many did it more often) in the previous year.

"We are so accustomed to this that we just think parents get carried away and that it's not harmful," said one of the study's lead authors, Murray A. Straus, a sociologist who is a director of the Family Research Laboratory at the University of New Hampshire. "But it affects a child. If someone yelled at you at work, you'd find that pretty jarring. We don't apply that standard to children."

Psychologists and psychiatrists generally say yelling should be avoided. It's at best ineffective (the more you do it the more the child tunes it out) and at worse damaging to a child's sense of well-being and self-esteem. "It isn't the yelling per se that's going to make a difference, it's how the yelling is interpreted," said Ronald P. Rohner, director of the Ronald and Nancy Rohner Center for the Study of Interpersonal Acceptance and Rejection at the University of Connecticut. If a parent is simply loud, he says, the effect is minimal. But if the tone connotes anger, insult or sarcasm, it can be perceived as a sign of rejection.

For many parents, allowing a child to run around naked at home is perfectly natural, an expression of physical freedom that represents the essence of childhood, especially in the summer. But for others, unclad bodies are an affront to civility, a source of discomfort and a potentially dangerous attraction for pedophiles. These clashing sensibilities can create conflict, even when the nudity in question takes place at home.

Often, the differences in viewpoint are generational. Rachel Sarah, 36, a writer and mother in Northern California, said that until her 9-year-old daughter, Mae, turned 7, she liked to wear only a T-shirt in the summer, a preference that Ms. Sarah found healthy, but that Mae’s grandparents could not accept. "My mom and stepfather were very insistent on her having clothes on for everything," Ms. Sarah said. Although most days Mae ran half-dressed through the sprinkler or played with friends under a hose, she had to accept different rules when her grandparents were around. "Their view, I would say, is that little girls need to have their clothes on unless they're taking a bath," Ms. Sarah said.

Aly Mandel, 41, a school psychologist and mother of five in Highland Park, N.J., said she, too, felt ire from extended family members for allowing her daughter Ava, now 6, to roam naked in and around the house when she was younger. "My mother, it used to drive her crazy how naked Ava was," Dr. Mandel said, explaining that the girl abhorred clothes. "My mother-in-law also, they both felt it crossed the line of what was appropriate. My mother-in-law would come in and automatically say, 'Ava, put on your clothes. Put on your underwear.'"

Gloria Schwartz, Dr. Mandel's mother-in-law, says she didn't have a problem with the nudity when Ava and her twin sister, Emily, were very young. But “when they got to be 3 years old, it bothered me," said Ms. Schwartz, 65, a real estate agent. "I would pull up to the house and the girls were running around naked. It felt inappropriate for them to be standing on the street in front of their house naked."