Poor modern-day parents. No wonder so many are confused and defensive about their child-rearing skills. At this point hardly any universally reliable, useful advice still persists on the parenting landscape. To whom can you turn for good counsel?

In her fascinating book Raising America — Experts, Parents and a Century of Advice about Children, author Ann Hulbert relates the history of 20th-century child-rearing advice. It’s an eye-opener. In any other field you expect to find a body of accumulated knowledge built on a foundation of hard information. But a century of advice has actually reduced the degree to which today’s parents share any beliefs with one another about how to rear kids.

Hulbert begins her story at the 1899 National Congress of Mothers. Its enthused participants — mostly members of mothers clubs — braved a fierce storm to attend, hungry for the expertise and scientific opinions that would help them elevate motherhood to a respected vocation.

The Congress’ keynote speakers were two eminent doctors, who represented the opposing poles of parenting advice, which you and I would call “strict” versus “permissive,” or “parent-centered” versus “child-centered.”

Dr. Emmett Holt, a nationally known pediatrician, had written The Care and Feeding of Children, which advocated a very strict diet regime and rigid feeding schedules. Impeccably groomed, he looked the part of a rationalist authority-figure and once described the child as a “delicately constructed piece of machinery.” Hulbert considers his best-selling book to be the 20th-century’s first “parent-centered” text.

The other speaker, Dr. Stanley Hall, had earned the first psychology doctorate in the country. He was the president of Clark University and a strong supporter of the Congress of Mothers. His approach to children was what Hulbert calls “Rousseauean,” letting the child take the lead and responding to her natural impulses. He was the first 20th-century leader of the child-centered, or permissive end, of the caretaking spectrum.

Already in the late 19th century, a new, almost religious belief in science had ousted much conventional wisdom. Grandmothers, for example, who had been the child-rearing experts since time immemorial, were displaced by experts, specifically men with degrees, whose beliefs were supported by data, or what there was of data at the time.

Hulbert says, “Where ‘mother love [had walked] hand in hand with care and anxiety,’ hobbled by outmoded grandmotherly lore, scientists of the new century would guide the way to calmness and consistency. Armed with up-to-date data, the modern mother could claim new authority and autonomy. Parenthood would become a prestigious profession. Furthermore, they believed, social equality would dawn in America, thanks to the spread of enlightened child-rearing down to the poorest and immigrant ranks. ‘Given one generation of children properly born and wisely trained,’ exclaimed an editorial in The New York Times extolling the National Congress of Mothers, ‘what a vast proportion of human ills would disappear from the earth.’ ”

From this optimistic start, Hulbert’s book proceeds chronologically through the 20th century, from one pair of similarly opposed experts to the next. Each builds his argument to support either strict or permissive child-rearing against the unfolding events of their times, including two world wars, the rise of feminism, and powerful economic swings.

The one exception to the pattern of dueling ideologues was Dr. Spock, the 1950s pediatrician who came to be the universally acknowledged expert for the boomer generation. Seeming to be part of the permissive camp, his reassuring mantra to the moms was “you know more than you think.” But even he, “who broke the mold by aiming for the middle, found he had to scramble to become the firmer, parents-take-charge counterweight to his own original child-friendly gospel.”

You and I know that every parent is challenged by daily decisions that strain any philosophy. No single approach works by itself. And in the end, after hundreds of pages, Hulbert concedes that the experts can agree on little that is definitively true about child-rearing.

What she doesn’t talk about is the extent to which child-rearing practices were largely a matter of communities passing on their social norms. In the absence of parenting norms for the culture as a whole, and for neighborhoods in particular, parents become more and more isolated in the work of rearing children by themselves. The stay-at-home moms in the 1950s talked to each other about raising kids. Families gathered together more often at religious, school and community functions, where just hanging out with each other created the sort of social pressure that shapes social norms.

With all due respect to the scientists, these “grandmotherly” norms are precisely what’s missing now — along with the communities that created them. For example, much as we say we wish teenagers would behave in ways that prevent premature pregnancy, a more powerful cultural expectation, to which we’ve all grown accustomed, is the sight of Victoria’s Secret models selling consumer goods to make some grownups rich. That’s the norm we’re passing on to the kids.

Hulbert shows that science has been used to support very different styles of parenting, but ultimately it is up to every parent to figure out how to succeed at this awesome responsibility. No wonder many parents seem to have given up even trying to sort it all out and allow their kids to do almost anything they want.

However useful scientific experts are, they don’t replace the benefit of people relying on their family, friends and neighbors for intelligence about raising kids.

Julia Steiny is a former member of the Providence School Board; she now consults and writes for a number of education, government and private enterprises. She welcomes your questions and comments on education. She can be reached by e-mail at juliasteiny@cox.net or c/o EdWatch, Education and Employment, The Providence Journal, 75 Fountain St., Providence, RI 02902.