It's easy to take the job description of motherhood for granted: Take care of your kids, in whatever way you can. The specifics, though, are a little trickier.
In fact, the meaning and duties of being a mom have undergone great upheaval just in the last century. Should moms work outside the home or stay with the kids full time? Does letting a baby cry scar it or strengthen it? Should moms be praised just for being moms?
The answers to these questions depend on the era in which they're asked. Throughout U.S. history, moms have been exalted, demonized and exalted again. Their instincts have been questioned and ruled sacrosanct. And they've taken the most guilt upon themselves during periods where they spend the most time with their children. [10 Scientific Tips for Raising Happy Kids]
Read on for five ways motherhood has changed in the United States.
1. More moms work outside the home…
Ah, the Mommy Wars. The media loves tension between stay-at-home moms and their work-for-pay counterparts — so much so that both the Huffington Post and conservative radio talk show host Rush Limbaugh have covered the topic in-depth. How much of this rancor filters down to day-to-day interactions between moms is arguable (and likely personal). But there's no doubt that more moms are bringing in a paycheck today than in the past.
In the 1950s, only 19 percent of mothers with small children worked outside the home, said Stephanie Coontz, a historian at The Evergreen State College in Washington and author of "A Strange Stirring: The Feminine Mystique and American Women at the Dawn of the 1960s" (Basic Books, 2011). As of 2008, more than 60 percent of moms with kids under age 6 were in the work force, according to the Bureau of Labor Statistics.
Working moms of older kids are even more common. As of 2008, close to 80 percent of mothers with children between ages 6 and 17 worked outside the home. That is a rise of about 10 percent since 1984.
Attitudes haven't kept up with reality, however: According to the Pew Research Center, only 16 percent of Americans think a mom who works full time is ideal for young kids. A third favor moms staying at home full time, and 42 percent think part-time work would be ideal.
2. … But they also spend more time with their kids
Cue the guilt machine: All that time at work takes away from time with the kids, right? Nope.
Moms (and dads) actually spend more time with their kids today than in the past. According to Pew time-use studies, mothers spent 10 hours a week on child care in 1965, while dads spent a paltry 2.5 hours taking care of their kids. As of 2011, moms were spending 14 hours a week on childcare and dads seven. The increase came despite the fact that moms' time working outside the home leapt from eight hours a week on average in 1965 to 21 hours a week on average in 2011.
Throughout most of the 20th century, "moms really spent very little time with their kids, because there were so many things they had to do around the home," Coontz told LiveScience. Today, mothers spend less time on housework and spend less time being alone or engaging with their communities in favor of spending that extra time with their kids, she said.
Attitudes toward what kids need have also changed, said Janet Golden, a historian at Rutgers University who is writing a history of babies in the 20th-century United States. Golden has gone to the horses' mouth to collect old parenting attitudes: She's been perusing old baby books filled out by parents since the late 1800s.
Parents have always loved their babies, Golden told LiveScience, but modern moms and dads are more concerned than past parents with shaping their children's futures.
"In the past, people would look sometimes to folklore and to early traits to predict their children's futures, but now they're very much engaged in trying to shape their child's intellectual development and are a little more nervous about that." [11 Facts About Your Baby's Brain]
Interviews with parents of previous generations reveal that moms were much less likely to have read to kids or helped them with homework in the past, Coontz said.
"We actually expect more from mothers and kids than we did in the past, even though we also expect them to have lives outside the home," she said.
3. Motherhood has been privatized
As the concerns of mothers have shifted, so have attitudes about how to solve parenting problems, Golden said. In the late 1800s and early 1900s, parenting advice focused on hygiene. Infant mortality was only just beginning its decline as doctors came to understand communicable diseases. (Believe it or not, it wasn't until the mid- to late-1800s that scientists realized that microorganisms cause disease.)
In that era, Golden said, parents welcomed the government into their families with open arms. The best-selling U.S. government pamphlet ever was a booklet first published in 1914 called "Infant Care." The book covered everything from how to change a diaper to recipes for baby food. Some of the advice is rather dated today: "The rule that parents should not play with the baby may seem hard, but it is without doubt a safe one," reads one section titled "Playing With the Baby." [9 Brainy Baby Abilities Explained]
The U.S. Children's Bureau, established in 1912, got 125,000 letters a year from mothers seeking advice, Golden said. Much of the government advice was about boosting public health and reducing infant mortality.
"Americans had a collective interest in infant welfare, and the government got involved with that at all levels and was very successful in some ways," Golden said. In contrast, she said, "today we seem to have a lot of rhetoric about getting the government out of our house."
4. Most people like moms more now …
Today, it seems like politicians can't get through a speech without praising mothers of all stripes. This wasn't always the case. In fact, mothers were once demonized as freeloaders who were destroying America.
In the 1800s, mothers had few legal rights to speak of, but they were idolized as the keepers of American moral values. Women were seen as responsible for raising strong sons who would, in turn, elevate the nation.
Things got ugly in the early 1900s. Sigmund Freud's theories of child development were all the rage, and they didn't always paint mothers in the best light — in fact, good old mom was often blamed for her children's problems.
"Over the first 80 years of the 20th century, mothers' reputations actually declined," Coontz said. "There was this tremendous attack on old-fashioned mothers who expected all this reverence just for being moms."
That mom-hate continued into the 1940s and '50s, Coontz said. In 1942, pulp sci-fi author Philip Wylie published "Generation of Vipers," a book claiming that American mothers were raising wimpy sons and demanding respect for nothing.
"Never before has a great nation of brave and dreaming men absent-mindedly created a huge class of idle, middle-aged women," Wylie wrote in the 1955 edition of the book.
If that passage doesn't suggest that Wylie might have had some issues, try this one, from the same printing:
"[L]et us look at mom.She is a middle-aged puffin with an eye like a hawk that has just seen a rabbit twitch far below. She is about twenty-five pounds overweight, with no sprint, but sharp heels and a hard backhand which she does not regard as a foul but a womanly defense. In a thousand of her there is not sex appeal enough to budge a hermit ten paces off a rock ledge. She none the less spends several hundred dollars a year on permanents and transformations, pomades, cleansers, rouges, lipsticks, and the like — and fools nobody except herself."
5. … Except other moms
Wylie's book had gone into 20 printings by 1955. Today, he would likely be verbally eviscerated by mommy bloggers and ignored after an initial whirlwind of righteous indignation.
"Outside observers are very respectful of mothers," Coontz said.
But moms are now their own worst enemy. Guilt and motherhood are almost expected to go hand-in-hand today, Coontz said: When they stay at home, moms fear they aren't contributing financially to the family or worry their kids won't respect them. When they go to work, they fret over neglecting their children.
"I think a lot of the so-called Mommy Wars really just stem from the fact that we feel constant guilt," Coontz said. When people feel tremendous guilt, she said, they turn it outward, becoming self-righteous and judging other mothers far more harshly than in the past.
Parental guilt even extends to relatively private spheres. The earliest baby books recorded stories of infants getting into scrapes, Golden said. Parents would tell a story of a kid falling out of a high chair or bumping its head with amusement. Modern parents, in contrast, do not record such incidents for posterity.
"I don't think babies stopped banging their heads by any means," Golden said. "But I think parenting expectations are such that it's seen as child abuse or something if your child has a fall."
The good news for guilt-ridden moms is that no one is as hard on them as they are on themselves, Coontz said. In 2000, parenting researcher Ellen Galinsky published "Ask the Children" (Harper), a study-turned-book in which she asked kids with working moms how they felt about their moms working. They thought it was great.
"Here's a Mother's Day present for moms," Coontz said. "Everybody else thinks you're doing good — lighten up."
Live Science newsletter
Stay up to date on the latest science news by signing up for our Essentials newsletter.
Stephanie Pappas is a contributing writer for Live Science, covering topics ranging from geoscience to archaeology to the human brain and behavior. She was previously a senior writer for Live Science but is now a freelancer based in Denver, Colorado, and regularly contributes to Scientific American and The Monitor, the monthly magazine of the American Psychological Association. Stephanie received a bachelor's degree in psychology from the University of South Carolina and a graduate certificate in science communication from the University of California, Santa Cruz.