A new book by Murray Straus, founder and co-director of the Family Research Lab and professor emeritus of sociology at the University of New Hampshire, evaluates decades worth of research to make a "definitive case" against spanking.

In his work, Straus found that spanking slows cognitive development and increases antisocial and criminal behaviour.

"The Primordial Violence" (Routledge, 2013) features longitudinal data from more than 7,000 US families as well as results from a 32-nation study and presents the latest research on the extent to which spanking is used in different cultures and the subsequent effects of its use on children and on society.

"Research shows that spanking corrects misbehaviour," Straus says. "But it also shows that spanking does not work better than other modes of correction, such as time out, explaining, and depriving a child of privileges."

He adds: "Moreover, the research clearly shows that the gains from spanking come at a big cost. These include weakening the tie between children and parents and increasing the probability that the child will hit other children and their parents, and as adults, hit a dating or marital partner. Spanking also slows down mental development and lowers the probability of a child doing well in school."

"More than 100 studies have detailed these side effects of spanking, with more than 90 percent agreement among them," he says. "There is probably no other aspect of parenting and child behaviour where the results are so consistent."

Still, as most parents know, disciplining kids can be tricky business. WebMD suggests that parents focus on rewarding good behaviour, be clear about rules to avoid confusion, and when your child is misbehaving, buy yourself some time to calm down before taking action. Parents magazine suggests that sometimes the best way to do so is with a time out, to give everyone a chance to cool off.

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  • 1. Breastfeeding is good.

    If there's one thing that researchers have confirmed in recent years, it's that breastfeeding has benefits. And several 2013 studies uncovered even more evidence supporting that fact: <a href="http://www.medicalnewstoday.com/articles/264080.php" target="_hplink">One found </a>that breastfeeding longer may help boost babies' intelligence, perhaps because breast milk contains DHA, which has been linked to cognitive development. <a href="http://www.huffingtonpost.com/2013/05/17/breastfeeding-adhd_n_3288462.html" target="_hplink">Another suggested</a> that breastfeeding may be protective against ADHD -- although it did not establish cause and effect (so it might be that other aspects of children's upbringing, for example, or genetics played a role).

  • Most medications are safe for nursing mothers ...

    A major American Academy of Pediatrics report issued this year concluded that the majority of medications are safe for nursing mothers, despite the fact that many women are counseled to discontinue their use. Some medications do transfer to breast milk, but the amounts tend to be small, while others do not transfer at all. The difficulty, however, is knowing which drugs are safe and which are not. "There are traditional medications, like aspirin, that have been around for years and that we have a lot of information about, we're secure in our knowledge," <a href="http://www.huffingtonpost.com/2013/08/26/medication-nursing_n_3806389.html" target="_hplink">one doctor told HuffPost</a>. "But there are new drugs coming out all the time, including new antidepressants and antipsychotics, and we know less about them."

  • Buying breast milk online is risky.

    Buying and sharing breast milk online has become increasingly popular, but it is not a particularly safe practice, according to data released in 2013. Researchers purchased samples from one of the most popular milk sharing websites in the U.S. and compared them to those from a milk bank (milk banks, which are regulated by the <a href="http://www.fda.gov/downloads/AdvisoryCommittees/CommitteesMeetingMaterials/PediatricAdvisoryCommittee/UCM235619.pdf" target="_blank">Human Milk Banking Association of North America</a>, follow strict guidelines and pasteurize their milk). The online samples had higher levels of contamination, with 64 percent testing positive for staphylococcous, and three of the samples testing positive for salmonella. Though many parents are, understandably, eager to provide their babies breast milk and may not be able to for various reasons, there is no getting around the potential risks: "There is hardly anything that, as a buyer, you could use to determine if a given sample is safe for your baby," <a href="http://www.huffingtonpost.com/2013/10/21/breast-milk-safety_n_4124682.html" target="_hplink">the study's researcher told HuffPost</a>.

  • The vaccine timetable is safe.

    A comprehensive review conducted by the Institute of Medicine (IOM) found that the current U.S. vaccination schedule is safe, and that there is no evidence that immunizing children against polio, whooping cough, measles and other diseases leads to health issues, such as autism or asthma. While the IOM said it hopes the findings will reassure parents and health care providers that current guidelines are safe, it also called for continued monitoring, <a href="http://www.huffingtonpost.com/2013/01/16/vaccine-safe-for-children_n_2488449.html" target="_hplink">Reuters reported</a>.

  • 'Flatspots' are common (and no cause for concern).

    Since the advent of the "back to sleep" campaign (aimed at reducing the risk of Sudden Infant Death Syndrome), the number of babies with "positional plagiocephaly" -- medicine-speak for flat spots on their heads -- has soared. A Canada-based study found that more than 46 percent of 2- to 3-month-olds have some form of the condition (most mild). Because the researchers didn't have past figures for comparison's sake, it's entirely possible that this has long been the case, and parents and doctors are just more aware of it now; or it could be because more babies are sleeping on their backs. Whatever the reason, the good news is that flat spots tend to be totally harmless.

  • Bedtime consistency matters.

    It's not just how much sleep kids get, but how regular it is that is important, according to a study out of the U.K. Children with consistent bedtimes scored better on reading, math and tests of spatial skills. And the effects appeared to be cumulative: Children who had inconsistent bedtimes when they were 3 (the researchers asked parents about their kids' bedtimes at ages 3, 5 and 7) scored lower at age 7. And kids who had inconsistent bedtimes at more than one of those ages showed more pronounced effects on their tests. It is not clear yet whether not having a set bedtime is simply a reflection of children living in "chaotic settings" where they were more likely to skip breakfast or have a TV in their room, the researchers wrote or whether the effect was more direct, but sleep experts say the message is clear: "I would tell you that in my estimation, the majority of parents have no idea how important sleep consistency is," <a href="http://www.huffingtonpost.com/2013/07/11/kids-bedtimes_n_3580201.html" target="_hplink">one told HuffPost</a>. "It's not because they don't care. They haven't been told."

  • Most packaged foods for toddlers have too much salt.

    <a href="http://www.huffingtonpost.com/2013/03/21/sodium-baby-food-_n_2925776.html" target="_hplink">One of the first studies</a> to take a close look at the amount of sodium in packaged foods made for toddlers found that 70 percent of them exceeded 210 mg of sodium per serving -- the threshold researchers used to classify a food as high sodium. And some of the toddler meals had roughly <em>half</em> of the maximum daily recommendation. Fortunately, baby foods fared better: Almost all of the commercial foods for babies up to one year were relatively low in sodium, the researchers found.

  • Childhood obesity is down.

    For the first time in decades, <a href="http://www.huffingtonpost.com/2013/09/16/childhood-obesity-kids-healthier-_n_3922637.html" target="_hplink">childhood obesity rates dropped</a> -- at least among low-income preschoolers between the ages of 2 and 4. These lower rates are, of course, good news but health experts say the overall numbers are still too high: One in 8 preschoolers in the U.S. is considered obese.

  • ADHD diagnoses are up.

    <a href="http://www.nytimes.com/2013/04/01/health/more-diagnoses-of-hyperactivity-causing-concern.html?_r=0" target="_hplink">A comprehensive <em>New York Times</em> analysis</a> of Centers for Disease Control and Prevention data released in 2013 uncovered a significant jump in the number of children who were diagnosed with ADHD in the past decade. Up to 11 percent of school-age children have been told they have disorder, according to the <a href="http://www.nytimes.com/2013/04/01/health/more-diagnoses-of-hyperactivity-causing-concern.html?_r=0" target="_hplink"><em>Times</em></a>, for reasons that are not yet understood. It could be, for example, that there is simply more awareness of ADHD or that children are being over-diagnosed. Or, perhaps, there are factors causing ADHD to be more prevalent than before.

  • Autism might be more common than previously thought.

    The prevalence of parent-reported cases of autism is up from 1 in 86 in 2007 to 1 in 50 between 2011 and 2012, <a href="http://www.huffingtonpost.com/2013/03/20/autism-prevalence_n_2909533.html" target="_hplink" CDC data revealed</a>. Researchers argued that the uptick was largely due to doctors identifying previously unrecognized cases of ASD, although it is also possible that other factors are at play. The 1 in 50 figure is, clearly, at odds with the <a href="http://www.cdc.gov/ncbddd/autism/research.html" target="_hplink">1 in 88 figure</a> provided by the CDC, which is often used as the best estimate of autism prevalence in the U.S. That estimate comes from data collected in health and special education records, whereas the 1 in 50 figure comes directly from parents.

  • TVs, high chairs, magnets and rides can all be risky.

    Research now shows that certain seemingly harmless things can prove risky for children. <a href="http://www.huffingtonpost.com/2013/07/22/tv-injuries_n_3625056.html" target="_hplink">One study found</a> that televisions injure roughly one child in the U.S. every 30 minutes -- largely by falling on them. Another showed parents should be vigilant when their children are in high chairs (around <a href="http://www.huffingtonpost.com/2013/12/09/high-chair-injuries_n_4411868.html" target="_hplink">9,400 young kids</a> in the U.S. are injured falling off high chairs each year, it concluded). Magnets also pose a risk: The number of yearly swallowing incidents jumped from roughly one child in every 200,000 in 2002 to six per 200,00 in 2010, <a href="http://www.reuters.com/article/2013/08/29/us-kids-magnets-idUSBRE97S13V20130829" target="_hplink">one study showed</a>). And amusement rides (at parks, fairs, restaurants and malls) injure more than <a href="http://www.huffingtonpost.com/2013/05/01/rides-injury-children_n_3187571.html" target="_hplink">4,400 children yearly</a>).

  • Bullying has physical (not just emotional) consequences.

    <a href="http://www.huffingtonpost.com/2013/09/16/bullying-physical-effects_n_3935056.html" target="_hplink">A startling study</a> found that when school-age children are bullied by their peers, they're twice as likely to experience so-called "psychosomatic symptoms," including headaches, stomachaches, dizziness, bed wetting and sleep problems. Sometimes, parents and teachers ignore children's physical symptoms or assume they're faking a stomachache, for example, to get out of an activity. But the study emphasizes that adults should take such symptoms seriously, as they might be a sign that something else is going on.

  • Yelling at kids can be just as harmful as physical punishment.

    Words matter, and so does the way they are delivered. <a href="http://www.huffingtonpost.com/2013/09/06/yelling-at-kids_n_3875832.html" target="_hplink">A study</a> concluded that harsh verbal discipline increases childrens' risk for depression and aggressive behavior (it focused on 13 and 14-year-olds) -- in much the same way that physical punishment often does. "The negative effects of verbal discipline within the two-year period of [the] study were comparable to the effects shown over the same period of time in other studies that focused on physical discipline," one of the researchers said in a statement.

  • Teens are engaging in healthier behaviors.

    Obesity rates appear to be "cresting" among adolescents and teens, <a href="http://www.huffingtonpost.com/2013/09/16/childhood-obesity-kids-healthier-_n_3922637.html" target="_hplink">a separate study found</a>. It also concluded that middle and high school students are engaging in healthier behaviors, like eating more fruits and vegetables and fewer sweets; skipping breakfast less often and exercising more. (The study did not establish a causal relationship between these healthier behaviors and the apparent leveling off in childhood obesity rates.) The amount of time spent watching TV also decreased, however, the amount of time teens spent playing video games or chatting online remained largely the same.

  • Marijuana might permanently hurt teens' brains.

    The <a href="http://www.huffingtonpost.com/2013/07/26/teen-marijuana-brain-adolescence_n_3653778.html" target="_hplink">study was highly preliminary</a> and conducted with mice, but it nonetheless generated a lot of attention for its finding that regular marijuana use during adolescence might damage brain function, putting teens at risk for psychiatric disorders down the road. The study is not the final word (indeed, a paper published in 2012 found teen marijuana use <a href="http://www.huffingtonpost.com/2012/12/21/teens-marijuana-brain-tissue-alcohol_n_2331779.html" target="_hplink">does not appear</a> to affect brain tissue health). But as the lead researcher explained, "Over the past 20 years, there has been a major controversy about the long-term effects of marijuana, with some evidence that use in adolescence could be damaging."