Posts Tagged ‘IQ’

Lead Poisoning

Friday, December 11th, 2009

Lead has no known function in the human body.  It’s an insidious toxin with a very broad range of symptoms, and even people who appear healthy can have dangerous levels of it in their blood.  The problem of lead contamination is entirely a result of civilization, since levels in pre-industrial people (in the range of 0.01 micrograms/deciliter (mcg/dl)) were around 100 to 1,000 times lower than blood levels typically found in people today.  (Lead Toxicity, A Review of the Literature. Part I: Exposure, Evaluation, and Treatment Lyn Patrick, ND)  

One of the major players in this disaster was the Ethyl Corporation.  In its pursuit of profits it criminally exposed workers to lead in its factories, and lied about it while they were dying.  Its lead-based-no-nock-gasoline-additive eventually put about seven million tons of lead out through the tailpipes of cars into the atmosphere. (1) (The Ethyl-Poisoned Earth by Alan Bellows)

The main cause of lead’s toxicity is its ability to interfere with many enzymes by binding to their sulfhydryl groups.  Short term measurable effects of lead poisoning begin at 25 mcg/dl.  Obvious symptoms begin to occur at levels above 40mcg/dl in adults, and above 60 mcg/dl in children. 

The list of potential health problems related to lead is a very long one:  Lead can damage hearing, vision, muscle coordination, the blood, kidneys, heart, and reproductive system.  Symptoms can include abdominal pain, anemia, loss of appetite, constipation, delayed growth, depression, diarrhea, fatigue, headaches, irritability, decreased libido, memory loss, muscle pain, nausea, personality changes, problems with sleep, an unusual taste in the mouth, weakness, tingling in the extremities, vomiting, and weight loss.  In one recent study those people with blood lead levels in the top 20% (over 2.11 mcg/dl) of the subjects had 2.3 times the odds of suffering from a major depressive disorder, and almost 5 times to odds of having a panic disorder as those in the lowest 20% (under 0.7 mcg/dl).  (The average blood lead level of the group was 1.61 mcg/dl.)  (Young Adults’ Blood Lead Levels Linked to Depression, Panic Disorder)

Exposure to even low levels might cause irreversible learning difficulties and mental retardation in children.  One study found that the IQ scores of children dropped about 7 points across the sample as children’s blood lead levels varied from 1 mcg/dl to 10 mcg/dl. (2) (Very Low Lead Levels Linked With IQ Deficits)  

The current consensus is that there is no safe level of lead exposure.  Lead accumulates in the blood, soft tissues and bone; and its half-life is weeks in blood, months in soft tissues, and years in bone. 

In the past lead was used commonly in house paint, as an additive to gasoline, and as a pesticide.  One piece of good news in all this is that the Clean Air Act has helped reduce air emissions of lead nearly 90 percent during the last 20 years.

If you have a problem with lead contamination there are a number of things you can do to deal with it: 

Make sure your child’s blood is tested for lead before age 2, and regularly to age 6, if there is the possibility of lead in the child’s environment.  The major treatments are removal of the source of lead and possibly chelation therapy (administration of agents that bind lead so it can be excreted). (Chelation therapy – Wikipedia)

Around the home anything that has paint or a finish made before 1978 in the U.S. could be a source of lead.  (It was banned in France and many other countries before 1920.)  So you shouldn’t use cribs, bassinets, highchairs, painted toys, or toy chests made before that date.  Lead paint is still sometimes found in toys and toy jewelry made today, so you should keep up on toy recalls by checking the lead recall lists. (Toy Hazard Recalls – CPSC)  Unfortunately, 75% of the nation’s housing has lead paint.  Broken down by time period, 90% of pre-1940 buildings have it, 80% of pre-1960 ones have it, and 62% of pre-1978 buildings have it. 

Keep children away from paint chips (which they might eat) by closing and locking doors.  You should create barriers between living and play areas, and the sources of lead.  Apply temporary barriers such as contact paper or duct tape to cover lead sources. 

Lead contaminated dust can be created by the friction of opening windows and doors, it might be blown in - coming from distant contaminated soils, or it can be generated during home renovation on a pre-1978 house.  Lead dust is invisible and will pass through most masks and filters, so, if you have to sand or strip old paint that may contain lead, be sure to use a high quality mask to prevent inhalation of lead particles.  Regularly wash children’s hands, pacifiers, toys, and any other items that might go in the mouth.  Feed children nutritious low-fat meals high in calcium and iron, since this will reduce the amount of lead absorbed into the body.  Wet-mop and wipe floors, window components, and other horizontal surfaces (counters, tables or floors) frequently.  If possible, windows should be kept shut to prevent abrasion of painted surfaces, or only opened from the top sash.  Don’t vacuum with a regular vacuum because it just lets lead dust fly around, but instead use a vacuum cleaner that utilizes a HEPA (High-Efficiency Particulate Air) filter.  Pregnant women and children shouldn’t be present during a pre-1978 house renovation. 

Lead was often in exterior oil-based paint prior to 1950, and as it ages it often contaminates soil about a house where children play.  Stop children from playing in bare soil and close to the sides of the house.  Instead, provide them with a sandbox more than 3 feet away from it.  (If your do have a sandbox, parents should cover the box when it’s not in use to prevent cats from using it as a litter box.)  Plant grass on areas of bare soil, or cover the soil with mulch or wood chips.  Take off your shoes when you go inside, and, if you walk barefoot outside, wash your feet when you go indoors.   Also, give your pet’s feet, legs, and undersides a rubdown with a towel after taking them outdoors. 

Lead solder can contaminate house pipes, so, unless you know your pipes are uncontaminated, you should only use cold water from the tap for drinking or cooking.  Also, if water sits in a pipe for several hours flush it from the tap for two minutes before drinking.  You can also use a water filter to reduce the lead in the water you cook and drink with.  For example, a simple Brita water filter will remove around 9o% of the lead found in tap water.  

Replace inexpensive, horizontal, plastic blinds that have been made in Asia or Mexico, since these types of blinds often contain lead.  Pregnant women and children should not be exposed to burning candles that could contain lead in their wicks.  Don’t drink out of crystal glass.  Soft vinyl lunch boxes can have dangerous levels of lead.  Avoid using any personal care products that contain significant amounts of lead. 

Hobbies that often involve working with lead are making stained glass windows, working with pewter and other collectible figurines, the glazing and firing of pottery and ceramics, making lead weights, reloading and making ammunition, making lead shot, target practice, making lead fishing weights or lures, refinishing furniture, and remolding.  You should never sand, burn, or scrape paint unless you either know it doesn’t contain lead, or take the proper precautions.  You should shower and change clothes after finishing a task that involves working with lead-based products.

Sites where lead might be a problem are hazardous waste sites, an area where cars are abandoned or repaired, ballast on a ship, a heavily traveled major highway or roadway, and an older house with peeling exterior paint.  Also artificial turf playing fields have recently been found to produce a potentially hazardous amount of lead dust.

Other sources of lead are kohl (a South Asian cosmetic), sindoor (a cosmetic used by traditional Hindu and Sikh married women), herbal remedies (Ayurvedic preparations (Ghasard, Bala Goli, and Kandu), surma, and those of Chinese origin), and folk remedies (azarcon (also called Maria Luisa, Liga, Alarzon, Alkohl, Greta, Coral and Rueda), farouk, bint al zahab, and pay-loo-ah).  Additional sources are solder which was used in the past to seal cans of food, ceramic glazes, lead curtain weights, lead bullets from hunted animals, bullets lodged in a person’s joints (since they deteriorate over time), imported candies that contain tamarind or chili, contaminated pottery, containers, cookware, or tableware.  Older Christmas tree ornaments might be decorated with lead paint, and lead is in some tree light wires.  Old newspapers, paper bags, magazines, and comic books could have been made with lead based inks.  You should never burn treated lumber, since there will be heavy metals in the smoke.  Industrial facilities, urban runoff, and atmospheric deposition are all sources of lead in the aquatic environment.  Even your keys can often contain small amounts of lead.

Types of work that is typically associated with the risk of lead contamination include house construction and repair, shipbuilding, painting (especially marine related painting), iron processing, brass or copper foundry valve and pipe fitting, bronze work, welding, resurfacing, bridge, tunnel, and elevated highway construction; the demolition of bridges, towers, and other steel structures; lead battery manufacturing and recycling, radiator manufacturing and repair, scrap metal recycling, the electronics industry, the manufacture of some plastics, automotive repair, fishing weight production, leaded glass manufacturing, lead ore production, milling, and smelting; and municipal solid waste incinerators. 

If your workplace poses a risk of lead contamination there are a number of safety precautions you should take:  You should work with your employer to reduce lead and lead exposure in the workplace, perhaps by providing special ventilation equipment and/or fitted respirators.  Wash your hands and face before eating, drinking, or smoking.  Eat, drink, and smoke only in areas free of lead dust and fumes.  Wet clean and HEPA vacuum lead-contaminated dust.  Use separate work clothes and shoes while at work, and keep your street clothes in a clean place.  Shower at work before going home, and launder your work clothes at work.  If you take your work clothes home, wash and dry them separately.

For more information there are a number of sources you can contact.  Here are some numbers: 

EPA’s Safe Drinking Water Hotline 1-800-426-4791.  

National Lead Information Center 1-800-LEAD-FYI, or 1-800-424-LEAD (5323). 

Lead Surveillance and Reporting, Office of Epidemiology, 1-360-236-4252. 

For information about lead in the workplace call the Department of Labor and Industries, 1-360-902-5663. 

For a list of qualified testing laboratories for analysis of lead in paint, soil, or dust call 1-800-424-LEAD. Please specify that you are requesting the NLLAP/ELPAT list of laboratories.  

HUD’s Lead Reduction Office, see: http://www.hud.gov/lea/leahome

For a home test, see: http://leadtestkit.com/kits1.html

You can also talk to your state or local health department about testing paint and dust from your home for lead.

To permanently remove lead hazards, you have to hire a lead “abatement” contractor.  Call your local paint stores to find out if the contractor you’re considering has a good history with the store.  Find a contractor who has been in business for several years, and can offer references. The longer they’ve been in business, the more they will likely know about lead.  Find a contractor with whom you feel comfortable, and who can answer your questions and explain their work.   

(1) Only one of the many consequences of this might have been a nationwide crime wave.  A number of recent studies have shown a strong correlation between atmospheric lead levels and crime rates.  The sharp decline in US crime rates, which began in the early 1990s, correlates perfectly with the reduction of leaded gasoline in the early 1970s.  Other countries have seen similar declines, also delayed by twenty years. (The Ethyl-Poisoned Earth by Alan Bellows)

(2)  Throughout this entire discussion there exists the common problem of inferring causation from correlation.  Since direct experiments with humans would be unethical, many results require an assumption that lead is actually the cause of a health problem.  At higher levels of contamination this assumption is unproblematic, but at lower levels this can be a source of uncertainty.  Looking at the national lead standards for blood toxicity through the years, in the space of about 50 years, they have changed six-fold from 60 mcg/dl to 10mcg/dl.  One reason to be skeptical of a 7 point IQ drop because of such low lead levels is that this suggests that people who grew up in the 1950’s and 1960’s would have had greatly reduced IQ’s, and this doesn’t seem to have been the case. 

In 1960, 60 mcg/dl
In 1970, 40 mcg/dl
In 1975, 35 mcg/dl
In 1985, 25 mcg/dl
In 1991, 10 mcg/dl

It is certainly possible that raising a child’s blood lead level from 1 mcg/dl to 10 mcg/dl directly causes an average 7 point drop in IQ.  The problem here is that there are potentially hundreds of confounding variables that could be creating the observed correlation.  It’s possible that children with lower IQ’s have a greater tendency to chew on paint chips, be less well-nourished, or attend poorer schools.  Also, parents with lower IQ’s might have a greater likelihood of living in lower quality housing and in more contaminated neighborhoods, be less aware of the dangers of lead poisoning, or be less competent when taking precautions, etc.  So, the connection between lead at low levels and IQ could be one of children inheriting genes from relatively lower IQ parents, which predispose them to also have lower IQ’s.  

In short, while it is entirely reasonable to take no unnecessary chances with lead poisoning (personally I would prefer my blood level to be literally zero), it’s only careful to remember that researchers haven’t actually established an airtight connection between the low blood lead levels and the observed health effects they are currently concerned about.  (From: Toxic Lead Levels by Valerie)

(Lead – CDC) (Lead – Prevention Tips – CDC) (Lead – Sources of Lead – CDC)  (Lead Poisoning Fact Sheet) (The Basics about Lead Paint – Home Safe Environment) (Lead Poisoning – Wikipedia) (How to Lower The Risk of Your Child Getting Lead Poisoning – eHow) (Simple ways to help prevent childhood lead poisoning - iVillage) (Helping Parents Prevent Lead Poisoning. ERIC Digest. by Binns, Helen J. – Ricks, Omar Benton) (Lead Poisoning: Prevention – MayoClinic) (Ways To Prevent Lead Poisoning by Dr. Ben Kim) (How to Prevent Lead Poisoning) (Prevention of Lead Poisoning – Cure Research) (Campaign for Lead Safety Awareness – Angie’s List) (Lead Poisoning Prevention – KeepKidsHealthy)

SES Status, Health, and the IQ Connection

Thursday, September 24th, 2009

I first ran across the health-socioeconomic status (SES) gradient in a Discover Magazine article about 10 years ago.  (Sapolsky, Robert. “How the Other Half Heals” Discover. April, 1998 pp 46-52)  Researchers have found that there is a positive relationship between status and health that holds across ages, races, genders, time periods, societies, and diseases.  The effect is so persistent that even identical medical treatments for the same medical conditions of equal severity show the same SES gradient in outcomes.  Just to be clear, the phenomenon that the researchers are interested in isn’t occurring between countries, because, past a certain level of national wealth, the differences flatten out.  What is of interest here is what is occurring within countries, between the different SES levels.  Numerous theories have been proposed to try to explain why this gradient keeps occurring. 

One school of thought holds that the direction of causation might be from poor health to low SES.  The idea is that poor physical or mental health could be causing poor job opportunities, and dysfunctional relationships, and thereby leading to low SES.  Another group of researchers suggest that poor intrauterine environments and/or inadequate childhood nutrition are major contributing factors.  Still another leading theory holds that low status, in and of itself, is the culprit.  This theory argues that as people rise in the status hierarchy their sense of self-control and self-esteem go up, and their sense of chronic stress goes down, which leads to better health.    

Part of the gap can be accounted for by differences in such health related factors as smoking, occupational related risks, alcohol use, high blood pressure, diet, exercise, quality of housing, exposure to pollution, social support, discrimination, crime, sun exposure, practicing safe sex, the stress of unemployment, and differential access to health care.  However, even after controlling for all these factors a significant part of the gap apparently persists.  One important set of studies, the Whitehall studies of British civil servants, showed the same pattern from the top to the bottom of the civil service hierarchy, even though all the persons in it had access to the same health care.  And it actually turns out that free health care, and government efforts at health education, don’t reduce the gap, but often widen it.      

A relatively new theory I find interesting has been proposed by Linda Gottfredson, who argues that one underlying explanatory variable is differences in IQ between the social classes.  The idea is that status correlates with IQ, and IQ correlates with health behaviors, so status will therefore correlate with health behaviors.  So, in effect, much of the SES health gradient is actually an IQ health gradient.  Supporting this idea, in one Scottish study, IQ scores at age 11 predicted the likelihood of survival to age 76.  And in an Australian veteran’s study, after controlling for other variables, each additional IQ point resulted in a 1% decrease risk of death by age 40. 

Gottfredson argues that much of what matters for health is determined by the individual, and that, in the end, people are their own primary providers of health care.  Much of people’s health knowledge is a natural result of self-directed learning, and those who have more knowledge to begin with are in a better position to take advantage of new information as it comes along.   In one study, knowledge of 10 classes of health information had a 0.9 correlation with IQ.  And many small decisions over time can have big effects over many years. 

Self-care is growing increasingly complex as new technologies are developed, and this is analogous to a job that can’t be routinized.  IQ has been found to be especially useful when tasks are novel, complex, unpracticed, and situations are ambiguous, changing, or unpredictable.  New treatments, complex regimes, and anticipating and taking precautions against the unexpected are all cognitively demanding tasks.  She also argues that much the same reasoning applies to accident prevention, and that the same IQ gradient occurs in this case.  (She points out that post traumatic stress disorder and resilience in children follow this gradient too.) 

Lower SES persons don’t follow their treatment plans as well, and seek less preventive care, even when it is free.  Just looking at the population in general, in one study researchers found that 33% of all prescriptions are taken incorrectly.  In another study, 42% of patients couldn’t follow directions to take their medication on an empty stomach, and in still another, 60% of insulin dependent diabetics didn’t know the steps to take to correct their blood sugar levels.  About 10% of hospitalizations happen because patients don’t manage their prescriptions correctly, and 30% of patients are estimated to be taking their medication in a way that seriously threatens their health.  

Finally, attempts to remedy this situation have led to providing health information in simplified form.  The protocols call for simple vocabulary, the omission of all non-essential information, providing no theory, requiring no inferences, and giving all the information in specific step-by-step instructions.  All of these modifications are consistent with helping a population with limited general problem solving abilities, or, in other words, low IQ.    

(Unraveling the SES Health Connection by James P. Smith, Intelligence Predicts Health and Longevity, but Why? by Linda S. Gottfredson, Intelligence: Is It the Epidemiologists Elusive ”Fundamental Cause” of Social Class Inequalities in Health? by Linda S. Gottfredson, What epidemiology omits: IQ by Dennis Mangan, Social determinants of health- Wikipedia, Population Health-Wikipedia,  IQ, Socioeconomic Status, and Early DeathCan Patient self-management help explain the SES health gradient? Just Health by Norman Daniels, The Socioeconomic Gradient, or Why Do Some People Get Sick and Others Do Not?)

Pregnancy & Child Related Information

Wednesday, September 2nd, 2009

I’ve previously blogged about how geophagy (eating clay) has been practiced for thousands of years to prevent morning sickness.  Pregnant women become hyper-sensitive to environmental toxins, and morning sickness helps protect the developing fetus from deformities.  It now turns out that all that misery could pay off for yet another reason, because women who have a greater degree of morning sickness might have more intelligent babies.  (Morning Sickness may be Sign of a Bright Baby)  The researchers involved theorize that the hormones which cause it might also protect a baby’s brain.  

S. Boyde Eaton, et al., have written (Dietary Intake of Long-Chain Polyunsaturated Fatty Acids during the Paleolithic, p. 20) that our brains are somewhat smaller than our Paleolithic ancestor’s brains, and that one reason might be our modern dietary deficiency in DHA omega-3 fats.  Along with DHA, it seems that, for rats, enriching the environment of the mother long before she becomes pregnant can affect the learning of her offspring.  Researchers theorize that the mother’s learning affects the nature of the hormones she will release during her later pregnancies.  This will affect epigenetic chemical markers on her offspring’s genes, which will in turn affect these genes’ expression during brain development, finally causing changes in the brains of the pups.  (Can Experiences be Passed on to Offspring? and A Mother’s Experience can Alter her Offspring’s Memory Performance)  Meanwhile, stress during pregnancy very likely harms a baby’s brain, and might increase the risk of schizophrenia.  Researchers think the mechanism is likely related to the stress hormone cortisol crossing the placenta.  (Stress Harms Baby’s Brain While in Womb)  Another possible factor that could increase the risk of schizophrenia is having the flue during pregnancy. (Flue During Pregnancy may Increase Risk of Schizophrenia in Certain Offspring

There are some indications that vitamin D deficiency is a risk factor for preeclampsia.  (Vitamin D for the Prevention of Preeclampsia?  A Hypothesis.)  This is a condition that occurs in pregnancy, which causes the patient to develop hypertension, along with protein in their urine.  It’s widespread, affecting about 10% of pregnancies, and is currently only treatable through termination.  It is most common in first pregnancies, and some researchers think that it’s the result of the mother’s immune system inappropriately attacking fetal cells.  The theory is that they are being triggered by the foreign antigens that were introduced by the father.  So, besides vitamin D supplementation, another recommendation is to delay pregnancy for a while after beginning sexual relations, on the theory that this allows the mother’s immune system to become acquainted with the father’s sperm’s antigens.  (Introduction and Overview of Evolutionary Medicine (p.24) by Wenda R. Trevathan, et al.) 

Low levels of vitamin D are also associated with chronic pain and muscle weakness, which suggests this might be a possible factor in a painful difficult birth. (Lack of Vitamin D Linked to Pain, and Recent Developments in Vitamin D Deficiency and Muscle Weakness Among Elderly People)  Stephan Guyenet, of Whole Health Source, reports that pelvic inlet depth index was larger in our hunter-gatherer ancestors (97.7% versus 92.1% today), and that this might be still another reason why childbirth is difficult for modern people.  (Longevity & Health in Ancient Paleolithic vs. Neolithic peoples)  Because vitamin K2 deficiency narrows the bone structure of the face, it seems natural to speculate that this could also be part of the reason for our lower pelvic inlet depth index today. 

Difficult births lead to caesareans, and, using MRIs, researchers have been able to show that women who have had c-sections had lower response levels to their baby’s cries.  This might indicate weaker bonding with their infants.  Researchers suggested that this possibly occurred because these women missed out on the hormonal priming from oxytosin that takes place during a vaginal delivery.  (C-sections may Weaken Bonding with Baby)  

Home birthing is as safe as in the hospital.  Two studies, one from the Netherlands and the other from Canada, found no evidence of greater death rates among home births, for low risk pregnancies, in either the mothers or their babies.  In the Netherlands study nearly 1/3 of those who started at home did end up being transferred to the hospital, but the risk was no greater than those mothers who had started out in the hospital.  Researchers said that a good midwife was the key. (Home Births “as Safe as Hospital,” and Home Birth with Midwife as Safe as Hospital Birth, Study) (See also: The Natural Family Site, and Why Have Natural Childbirth?) 

Also, as I previously blogged, some people claim that placenta eating can prevent postpartum depression.  (Placenta Benefits.info)

The natural childrearing people argue against circumcision on a number of grounds, including that they believe there doesn’t seem to be much of a reason for it.  (Put Down that Knife!  11 Reasons not to Circumcise, Circumcision – Wikipedia, and Circumcision Rates)

Pacifiers reduce the risk of sudden infant death syndrome (SIDS) by about 90%.  (Pacifier Greatly Reduces Risk of Sudden Infant Death)  They reduce the risk regardless whether or not the infant sleeps on his/her stomach, in soft bedding, or his/her mother smoked.  Problems such as thumb sucking, tooth development, and difficulties breast feeding can be avoided by waiting a few weeks before using one, and stopping when they become toddlers.  (However, there apparently is a trade-off, because, according to Gabe Mirkin, studies from Finland found that children who use pacifiers are more likely to have recurrent ear infections.)  Other people also recommend co-sleeping as protective.  (See below)  One more way of lowering the risk of SIDS is by using a fan to circulate the air in the room.  This reduces the risk by 72%. (Fan Use Linked to Lower Rate of Sudden Infant Death)  (See also: Sudden infant death syndrome – Wikipedia)

Coming to very similar conclusions as The Continuum Concept by Jean Liedloff, here is an article on Evolutionary Psychology: Natural Parenting - Back to Basics in Infant Care by Regine A. Schon.     Matt Metzgar wrote up this outline.  (I inserted some additional materials and links):  

Evolutionary Function of Crying (For a second opinion see: Should Infants be Allowed to Cry Themselves to Sleep?)

  • Crying signals genuine needs of the infant
  • Crying should be immediately attended to by the mother or caregiver
  • Crying takes significant physical effort on the part of the infant
  • The immediate response to crying should be to restore physical contact between the caregiver and the infant

Infants as Carried Young

  • Hunter-gatherer women carried their infants in slings close to the body
  • This increased beneficial skin-to-skin contact between the mother and the infant
  • The common leg positions of babies suggest they are adapted for carrying

Cosleeping  (Regarding co-sleeping: Mr. Metzgar cites this article (which argues in favor of it), Why Babies Should Never Sleep Alone: A Review of the Co-sleeping Controversy in Relation to SIDS, Bedsharing, and Breastfeeding, and this site, Mother-Baby Behavioral Sleep Laboratory.  See also: The Benefits of Co-Sleeping)       

  • Cosleeping for the infant and mother has been the universal norm throughout most of human history
  • Bedsharing is the environment to which the vulnerable newborn is best adapted
  • Cosleeping may reduce some forms of SIDS

Breastfeeding (See also: Breastfeeding Linked to Smarter Babies (Again)  This article points out that, as well as being correlated with 5.9 points of higher IQ, breastfeeding also apparently reduces the chances of a mother later developing rheumatoid arthritis, and lessons the child’s odds of later developing cardiovascular disease.  This article, Big Bad Cavities: Breastfeeding is not the Cause, states that more than three dozen studies have shown no link between breastfeeding and the disease of Early Childhood Carries (ECC).  Medical News Today reports that the concentration of volatile organic compound toxins in breast milk are much lower than indoor air, and also much lower than the safe levels for drinking water. (Concentrations of Certain Toxins in Breast Milk are Low, Study Finds))

  • No alternative to breast milk existed before the transition to a farming economy
  • Therefore, infants have been breastfed for 99% of all human existence
  • Artificial substitutes have been unable to replicate the complex structure of breast milk
  • There is mounting evidence about the many benefits of breastfeeding on child development

Extrogestation

  • Human infants are born in an exceptionally immature state
  • The conditions for the early part of infant life should attempt to mimic that of the womb
  • This includes close contact with the mother’s body in a tight, warm embrace
  • Heartbeat sounds are comforting to an infant; women tend to hold infants on the left side of their body, close to their hearts
  • Rocking an infant provides a calming effect since it mimics the movement stimulation the infant received from the mother’s normal daily movements
  • Swaddling replicates the feeling of the womb and has been proven effective in calming infants

Toilet Training  (What is Infant Potty Training, Benefits of Infant Potty Training, Infant Potty Training, The Controversy over Infant Potty Training, Shaping self-initiated toileting in infants)  (There are also major health benefits of squatting instead of sitting for defecation.  (The Squat Toilet)  The repeated refrain is to do things the way nature intended.)

  • Infants were historically toilet trained much earlier than in modern times
  • Natural toilet training depends on reading an infant’s signals and responding appropriately
  • Children trained in this way complete toilet training anywhere from 6 months to 2 years

Matt also reviewed this book, The 90-Minute Sleep Baby Program.  As he says, the basic idea behind the book is that humans have a 90 minute cycle of activity and rest.  This means that when a baby wakes up their next nap should be 90 minutes later.  (Older children might string several of these together.)  22 out of 27 reviews on Amazon gave the book 5 stars.  Matt speculates that many children today are sleep deprived, which is obviously troublesome.  It turns out that sleep deprived children have twice the risk of becoming obese.  (Sleep Deprivation Doubles the Risk of Obesity in Both Children and Adults

Matt also very favorably reviewed, The Happiest Baby on the Block.  The author argues that babies need a uterus like environment, and he suggests a number of tactics for mimicking it.  These include swaddling, shh sounds, side/stomach position, swinging, and sucking.  He claims that his program will calm almost all babies.  

Matt also pointed out Baby Sign Language, which allows the infant to communicate his/her needs at a much younger age.  I think it’s very surprising that this wasn’t stumbled upon thousands of years ago, yet it is a remarkably simple and wonderful advancement.  It apparently isn’t some sort of silly fad, but brings real benefits, which I think all parents would appreciate, including greatly reduced frustration on everyone’s part, and increased language skills. 

Matt has blogged about Baby Led Weaning, which takes the position that children shouldn’t be fed pureed foods (Pureed Food “isn’t Natural for Babies’), but instead weaned directly onto solid foods.  The argument behind the idea is that this is much closer to the way our ancestors would have done it.  (It should be said that hunter-gatherers often did pre-chew the child’s food to help him/her along.)   

I have blogged before about going barefoot, and children who go barefoot as long as possible have about half the rate of flat footedness later on.  Having said that, being flat footed doesn’t appear to be as big a problem as people once thought.  There appears to be no relationship between the height of children’s arches and their ability to perform athletically, and it very well also might not affect their injury rates. (Flat Feet don’t Impair Kid’s Motor Skills)  

A study from Sweden concluded that risk factors for snoring as an adult include respiratory and ear infections as a child, being raised in a large family, and being exposed to a dog at home as a newborn. (Have A Dog? Your Child is More Likely to Snore as an Adult) 

Children who suffer from cyclic vomiting might actually be suffering from migraines. (Gabe Mirkin: Cyclic Vomiting

Low levels of carbon monoxide, 25 parts per million, might cause oxidative stress on the cochlear nerve, and permanently damage the hearing of children.  Such carbon monoxide can come from tobacco, cooking, and heating appliances.  (How Chronic Exposure to Tiny Levels of Carbon Monoxide Damages Hearing in Young Ears)  However, the main cause of hearing loss in modern world is loud noise.  The blast from a single gunshot, or the loud prolonged noise of a rock concert, can result in permanent hearing loss and tinnitus (ringing in the ears).

Many cases of bed-wetting might be caused by breathing problems.  63% of bed-wetting children stopped when they had surgery to remove their adenoids or tonsils, and the use of a plate to widen the palate of bed-wetters with narrow palates ended the condition in 70% of cases. (Breathing Troubles the Cause of Bed-wetting?)   Gabe Mirkin discusses another theory, that it’s the lack of antidiuretic hormone that causes the problem.  This hormone causes the kidneys to shut down at night.  (Bedwetting

The BBC reports that a 10 minute test for dyslexia has been developed that can be used starting at age 3 & 1/2.  (Early Warning Test for Dyslexia)  The test has children repeat sentences and re-tell a story while looking at how the child builds sounds up into words.  For parents of children who seem a little different there is the book, Quirky Kids: Understanding and Your Child Who Doesn’t Fit In- When To Worry And When Not To Worry.  One reviewer thought the book would be most helpful to parents who are just beginning to suspect something is unusual, but don’t know what might be the problem.  It also debunks a number of folk myths out there, and reportedly has a good section on the pros and cons of various medications.  Science Daily has this article, Specific Behaviors Seen in Infants Can Predict Autism, New Research Shows, which reports that Canadian researchers have discovered that there are behavioral signs that can accurately predict autism in children as young as one year old.  (See also: The Vitamin D Theory of Autism)

According to a study by the University of Rochester Medical Center, there is no detectable risk to children from the mercury in the seafood their mother’s ate, up to 12 servings a week.  The study period was before birth to age 9, and the children were tested for 21 different cognitive, neurological and behavioral functions.  These abilities included concentration, attention, problem-solving, and motor skills. (No Detectable Risk From Mercury in Seafood, Study Shows

Tonsils serve to trap germs and train the white blood cells when children are young, but as they grow older their importance lessons.  Doctors generally seem to say that their removal can be justified if they obstruct the throat, or the child suffers from frequent throat infections.  (Dr. Alan Green on Tonsil Removal)    

Not surprisingly, mother’s who talk about people’s mental states, such as beliefs, wants, and intentions, have children with a greater understanding of social interactions.  (This obviously does not establish causation, because mothers with greater social skills might pass on genes that also dispose their children to have those same skills.)  Researchers note that these greater social skills do not necessarily imply that these children will be better behaved. (The Secret to Building Children’s Social Skills)   The Incredible Years is an organization which hosts a variety of programs for teaching parents, teachers, and children social skills.  It turns out the ability of a mother to read her child’s emotions is more important than her social status for the child’s development. (Why Mind-Reading Mums are Best

Not surprisingly, children are happier who have a sense of spirituality, that is meaning in life, and they think that their lives have value.  Good interpersonal relationships also helped, and accounted for 27% of the happiness variation between children.  Being more sociable was also a happiness predictor.  (Spirituality is key to kids’ happiness

Researchers want to know why some children are resilient in spite of bad upbringings.  They have found that resilient children tend to share a number of characteristics:  They have at least one supportive person in their life, have a positive outlook, a pleasant altruistic personality, they are eager to learn, and have problem-solving skills.  They take responsibility for their mistakes, and move on.  They also have an interest or friend they can turn to when they need to.  (This description to me sounds somewhat like the characteristics of lucky people.)  (Raising Resilient Children Foundation, their book, Psychosocial Characteristics of Resilient Children, and The Resilient Child)

Sara Bennett and Nancy Kalish, in The Case Against Homework: How Homework is Hurting our Children and What We Can Do About It, argue that there’s almost no evidence that homework helps kid’s academic success.  They point out that the amount of homework has skyrocketed in recent years, which is contributing to an epidemic of obesity, and robs kids of the time they need to be kids.  They also give advice on how to separate useful assignments from the time wasters.  Richard Louv, author of, Last Child in the Woods, argues that children suffer from a nature-deficit disorder. 

For preventing myopia, besides a low glycemic diet/ Paleolithic Diet, it seems that playing outside is also protective.  Researchers in Australia have found that kids who spend a lot of time outside have lower myopia rates. (Kid’s eyes need the great outdoors)   

I have previously blogged about The Freedom to Learn site.  Peter Gray has a series of articles which argue that play is essential for healthy human life, and maintaining a band’s existence.  John Holt takes a similar approach in his books, How Children Learn and How Children Fail, that children are natural learners, and the process of forcing them to learn in school changes their personalities for the worse.  David Elkind’s book, The Power of Play: How Spontaneous Imaginative Activities Lead to Happier Healthier Children, argues that play is changing from teaching children social roles, vocations, and academic skills to teaching them brand loyalty, fashion consciousness, and group think.  Matt Metzgar reviewed Susan Linn’s book, The Case for Make-Believe: Saving Play in a Commercialized World, which argues that many of today’s toys are scripted, and that they don’t foster the development of social and critical skills.  Matt also discussed this article, Sucker-Me Elmo, which questions the merits of electronic toys.  Meanwhile, New York City is developing the next generation playground, which is designed to foster the imagination of kids. (New York developing a next-generation playground)  Here is a site that features educational products for children We Make Stories, which allows the child to write and print their own stories.

It turns out that pedophiles don’t randomly search through MySpace sites searching for kids.  Instead they go for those kids in chat rooms who are presenting themselves in sexually suggestive ways. (Welcome to Crimes Against Children Research Center, and Salon – Stop Worrying about your Children)  This information is from the same woman who runs Free Range Kids, which I have written about before.  Boing Boing favorably reviewed this book, If Your Kid Eats this Book Everything will Still be Okay: How to Know if Your Child’s Injury or Illness is Really an Emergency by Lara Zibners.  Zibners is an emergency room pediatrician who says that 75% of late night emergency room visits are unnecessary, and this book is a guide to all the things you don’t have to worry about.

On the other hand, there are real risks out there, and Dreambaby makes safety products to help reduce these.  Science Daily has a story, Homes Need More Protection Against Falls, which points out that falls are the second leading cause of death among children, and that this is because many homes have inadequate protection against them.  Such homes are lacking such commonsense things as banisters, grab bars, anti-slip bathtub strips, and child safety gates.  Eco Child’s Play has a similar outlook, and advocates ”Green Parenting for Non-Toxic Healthy Homes.”  This site focuses on alternative medicine, and sources of toxins from such things as plastics, medicines, and cleaners.  (See, for example: 12 Warnings for Parents and Kids in 2008, 10 Ways to Avoid Toxic Plastic - BPA (Bisphenol A), Synthetic Estrogens and Your Child, Smart Medicine for a Healthier Child, 9 Best Articles for Natural and Home Remedies on Echo Child’s Play in 2008, Another Reason We Can’t Trust the FDA, Melamine…, New Study Suggests Link Between Hairspray Exposure and Genital Birth Defect, How Safe is Your Child’s Playground?, Balloons Cause More Deaths than Marbles, and Finding Safer Products for our Children)  They also discuss products to make parent’s lives easier. (Postpartum Bamboo Belly Wrap Helps Shrink Your Belly and Prevent Stretch Marks, and Why Tilty is a Better Sippy

In recent years people have been taking bullying far more seriously, and researchers have found that, at least with rats, bullying might scar the brain for life.  When rats were bullied new brain nerve cells would form, but then die, and they acted depressed.  (Bullying May Scar Brain for Life

Psychologist Randall Flanery has this advice for being a great dad:  Run a benevolent dictatorship.  Be friendly, but not a friend.  Admit when you’re wrong.  Remain firmly flexible.  Stick around even when they don’t want you to.  Ask questions.  Don’t take it personally if they express unhappiness.  Know that parenting is 24/7, and then some.  Keep in mind that who you are is more important than what you buy them.  Laugh.  Of course, there is also the book, Supernanny: How to Get the Best from your Children by Jo Frost.  For the sport parent, there is Who’s Game is it Anyway: A Guide to Helping Your Child Get the Most From Sports, Organized by Age and Stage by Amy Baltzell.

The Myth of Creative Genius

Thursday, August 20th, 2009

I had a class in cognitive psychology in which we studied theories of how people go about thinking through problems.  One of the most interesting things we covered in the course of the class was that the way most people think about creativity is fundamentally confused. 

People typically think about creativity as being what is called a psychometric trait, similar to the way they think about math ability.  A trait exists when people have a fairly stable characteristic way of responding, performing, or being that consistently accounts for differences between them.  Introversion, IQ, and height are all examples of traits.  A problem with the view that creativity is a trait is that, unlike math, researchers have never been able to construct a reliable and valid test for it.  If a test isn’t reliable this means that when a given subject takes the same exact test twice over a period of time he/she will score inconsistently.  For example, they might score high the first time and then low the second; and this is what often happens with tests of creativity.  If a test isn’t valid then it isn’t measuring what it’s supposed to.  An extreme example of this would be if someone was mistakenly attempting to measure a person’s blood pressure using a glucose monitor.  The number they would get wouldn’t tell you what you wanted to know, because you had measured the wrong thing.  This is also what happens with creativity tests.  When researchers gave a select group of highly regarded creative architects a large battery of tests, trying to discover what made them so creative, it turned out that there was no difference between their scores and their average non-highly-creative peer’s scores.   What this implies is that whatever it was that was making them creative wasn’t being captured by any of the tests the researchers had used.  

Partly as an outgrowth of these results, there has emerged a different view of what creativity involves.  This view holds that what people are seeing as the creative output of a genius is actually a kind of natural illusion.  That it is sort of like a mirage, and, just as with a mirage, there are a number of conditions which make this illusion likely to occur.  Creativity is typically associated with a person who is in a field that requires a fair bit of esoteric knowledge, or skills, or both.  The person has studied for many years.  They are gifted at that set of abilities that is relevant to the tasks of their field.  They are passionate about it, and hardworking at it.  When all these elements come together a person might produce a breakthrough of some sort: the theory of evolution, the periodic table, Mendel’s genetics of garden peas, Calder’s mobile, etc.  What follows next explains the illusion.  There is a crucial difference in how the peers of that person react and the public reacts.  The person’s peers, knowing the field as he/she does, often regard the breakthrough as a very clever piece of work, but one that is understandable.  A typical reaction might be, “Darn, I was so close!”  From the point of view of an uninformed audience member the view is very different.  What they see is a miracle.  “How could anyone ever have thought of that?  That person must have something extra, akin to a magical ability that I know I certainly don’t have.”  And this is how the theory of creativity was born. 

If we look briefly at what Calder had been exposed to before he came up with the mobile its creation seems, perhaps unfairly, almost inevitable.  He had seen mechanical self-animated toys, and applied the principles to creating his own miniature mechanical circus.  He had also been exposed to abstract shapes of Piet Mondrian.  Initially he put these two lines of artistic expression together, and created mechanical moving sculptures.  Finally, he eliminated the mechanical parts, and let the wind do the work of moving the shapes around.  Once you see all the precursing elements, the act of creation looks far less magical.  Although, to be fair, obviously when coming up with a new idea, it’s not nearly as obvious as it looks after the fact.

An analogy to a magic trick isn’t a bad one.  If you had an audience totally unfamiliar with stage magic, and a performer then proceeded to cut several women in half and levitate them, what would they think?  They might naturally conclude that this person had some special magical ability.  But, if now you were to take them up on stage and show them how the illusion worked, they would change their minds and say, “This is very clever, but it isn’t magic.  So, in the end the more you understand about a field, the less it looks like magic.  The more it looks like just clever and insightful problem solving, and not some sort of creative leap of imagination coming from some sort of special place that separates these people from the rest of humanity.

For further reading try: Creativity: Genius and other Myths, Creativity: Beyond the Myth of Genius, and Creativity: Understanding Innovation in Problem Solving, Science, Invention, and the Arts, all by Robert W. Weisberg

Myopia, Reading, Diet, Brain Size, and IQ

Friday, July 31st, 2009

One commonly accepted theory about what causes myopia is that the near point focus involved in reading in genetically susceptible individuals causes them to become nearsighted.  From what I have read this is almost certainly part of the explanation. 

But there is still more to this story.  Non-literate populations have roughly 1% nearsightedness, compared with developed countries in Europe and the United States, with rates of about 30%, and rates as high as 80% in developed Asian countries.  Normally when a country begins to industrialize, and the kids are put in school and therefore reading all day, the levels go up to the developed countries’ rates.  This is what happened to Eskimos.  However, one South Pacific Island, Vanuatu, in the 1980s had children in school all day long, and yet their rate of myopia was still only 1.3%.  What explains the difference is that their traditional diet hadn’t changed.  What appears to be happening is that glycemic spikes, which occur when people eat high index glycemic foods, lead to chronic hyperinsulinaemia.  This condition affects the hormones in the eye as it develops, which causes it to become myopic.   So at the end of the day you need three things to become myopic:  the gene(s) that make you susceptible, near point focus work, and a high glycemic diet. 

You might conclude from all this that it’s a bad thing to have the gene(s) which make you susceptible to myopia, but there’s another side to that part of the story.  It turns out that those children who become very nearsighted at a young age have about 7-8 points higher IQs.  Apparently it isn’t a case of smarter children reading more and becoming nearsighted as a result.  The eyes of these children are slightly larger at birth, and people with higher IQs have slightly larger brains when you control for such things as body size.  The back of the eye is considered part of the brain, and it seems that whatever the gene(s) are doing is affecting both the eyes and the brains of the people who have them.  Myopic children also have different values, language abilities, and sports participation patterns than non-myopics.  So there’s a tradeoff.  The genes that make you susceptible to myopia also make you smarter.  

If there’s a lesson to be learned from all this it’s that people were designed to eat a low glycemic, ideally Paleolithic Diet, and when we don’t we create problems for ourselves.

Height and Intelligence

Wednesday, July 22nd, 2009

From Matt Metzgar: “Here’s an interesting study that looks at leg length and fertility.  Long legs are generally thought to be attractive in women.  This study sets out to show that long legs are an indirect sign of reproductive capability.

The researchers found that women with longer legs had more offspring.  This was especially true for women from poorer backgrounds.  Therefore, it looks like there is an evolutionary reason why long legs are perceived to be attractive.”

From Gene Expression: “Interestingly, the height-IQ correlation is entirely due to differences in leg length, since the correlation vanishes when sitting height is used instead of standing height. The simplest explanation that Jensen & Sinha propose is that there is cross-assortative mating between female leg length and male IQ. They summarize several studies which show that tall women, no matter what economic class they are born into, tend to climb the economic ladder more easily and marry higher-status husbands. That pools tall and smart genes into the same family, but any given kid of theirs doesn’t get to pick and choose which parent he gets his height or IQ genes from, which explains why height and IQ are uncorrelated within families. Moreover, this is not a pattern only among the rich and bright: at every level of IQ, the pattern holds….”

So, the theory goes, long legs are an indirect sign of reproductive capability (because of some biochemical quirk of nature).  Therefore genes which make male minds find long legs attractive are selected for in general (because such males leave more offspring).   Those males with more to offer on average get the more desired mates.  Smarter males on balance will have more to offer.  So genes which code for higher IQ will co-assort with those genes which code for longer legs.  The end result is that taller people will be a little smarter.  (But, as a caveat, the correlation is weak, only .15 between height and IQ)