Some Additional Surprises Related to Autism



 Autism is unusually low among children of unmarried women, even though general intellectual disability is over twice as high among children of unmarried women.   

See in the chart below that children of single mothers have a relatively low ­Odds Ratio of having autism with intellectual disability (for ASD + ID, their OR is only 0.74), even though they have a high odds ratio of general intellectual disability (for Mild-moderate ID or Severe ID, their OR’s are 2.48 and 1.96.


This seems to point to an origin of autism that is very different from that of general intellectual disability.  The following is a possible explanation for how the two seemingly-related disorders apparently have origins in very different causes:

a)  Women who have babies outside of marriage may often have genetically-determined mental abilities that are inadequate for carefully considering the likely consequences of their actions, so a high percentage of general mental disability among children of unmarried women is to be expected, on the basis of genetics.  

b)  According to CDC data, single mothers are half as likely as married mothers to breastfeed their infants; (3)  think about that in relation to the fact that breastfeeding exposes infants to many-times higher doses of developmental toxins than are received by non-breastfed babies.(3a)  This is clearly a non-genetic exposure, and one that tends to be either low or high depending on the marital status of the mother.  Children of unmarried women are far less likely than children of married women to be exposed to this known source of developmental toxins, and they are far less likely to become autistic.  This would seem to be a good explanation for why autism with intellectual disability should be low among children of unmarried women while general intellectual disability (likely to be genetically determined) is high within that same category.  But if anybody has an alternative explanation to suggest, please send it to for inclusion below.






Other initially-mysterious relationships that were introduced in the "Introductory Summary" of this paper, as follows:


---  Autism is twice as prevalent among children of parents of high socio-economic-status (SES) as among children of low-SES parents. (see "Table 3" below)  This is surprising at first, since it is the opposite of what would normally be expected to result from genetic effects.  But consider the fact that breastfeeding is about twice as frequent among college graduates as among high school graduates (in the U.S., U.K. and Australia),(3b) imparting neuro-developmentally toxic dioxins to infants in doses scores of times higher than the EPA-estimated safe dose.(3a)


The disproportionately high breastfeeding rate among high-SES mothers would be hard to find in countries in which breastfeeding is nearly universal, as it is in the Nordic countries.  Perhaps not by coincidence, higher autism rates among high-SES children have not been found in studies carried out in countries in which there is no high-SES/low-SES difference in breastfeeding rates.(3f)



The reader should keep in mind that this chart is about autism (ASD) rates, showing them to be twice as high among children of U.S. parents of high socio-economic status (SES) as among children of low-SES U.S. parents.  It would be easy to confuse the above with a chart showing breastfeeding rates among high-SES mothers compared with those of low-SES mothers, since breastfeeding rates also have the very same relationship shown here; that is, they are basically twice as high among high-SES U.S. mothers.  Knowing about the disproportionately high levels of developmental toxins ingested by infants of high-SES U.S. parents helps one understand their very similarly high rate of autism. (Sources of above table and related information at (11))




 - - A fourth child’s risk of autism is half as high as that of a firstborn, on average.  And the odds of being diagnosed with autism continuously decrease from first to later children.  Infants later in birth order are less likely to be breastfed, they are breastfed for shorter periods on average, and the milk they receive has toxin levels that have been reduced as a result of excretion to earlier-born infants during previous breastfeeding.  (see Section1.2.s.1.c  at 


- - Every one of the high-autism U.S. states, OECD countries, and demographic groups has an unusually high rate of feeding their infants one specific kind of food (human milk),(3a)  

- - every one of the low-autism U.S. states, OECD countries, and demographic groups has an unusually low rate of feeding their infants that same specific food. (see "Correlations" in the fourth paragraph at for links to sections providing sources of this information)


- - There are times as many males as females among the autistic, even though the gender ratio among the mentally impaired was equal in earlier decades.(3e)  A dramatic increase in mental disability among males is compatible with the facts that (a) their neurological development depends heavily on presence of testosterone, and (b) the dioxins and PBDEs that are hazardously high in the increasingly-ingested contemporary human milk are known to reduce levels of testosterone, on the basis of animal tests .(3g)



---  Despite claims from various sources that breastfeeding is beneficial:  there are well-documented reasons to see the more highly-breastfed generations' health to be much worse than that of the low-breastfed generation that came earlier, as indicated by CDC and other authoritative data for 1970's to present.  The more-breastfed generations of children and young adults have the following: -- three and four times the obesity at a given age compared with the low-breastfed generation;(5) -- dramatically increased levels of asthma and other allergies,(6) – greatly increased ADHD, serious emotional and behavioral difficulties,(7) and (probably) autism;(8) -- greatly increased diabetes and other important diseases during childhood,(9) --  and increased childhood cancer, while adult cancer has declined.(10)  (See for a summary dealing with most of the above.)  Such unfavorable outcomes, in the face of official predictions of reduced disorders expected to result from breastfeeding, should be seen in light of the fact that the studies on which claims of benefits of breastfeeding are based are acknowledged by the U.S. Surgeon General to be of the "observational" type,(3c) which the U.S. Agency for Healthcare Research and Quality points out are subject to false conclusion.(3d)  The recognized high levels of toxins in contemporary human milk in developed areas are another part of the explanation.  A final influence is the effect of the immune cells in breast milk, which reduce infections during infancy, but in doing so (in the already sanitary conditions in developed countries) deprive the body of microbial challenges that would otherwise be stimulating the immune system's development.(see "Immunity Effects" in the Introduction section of



-- Stable prevalence of autism in the U.K. while it grew rapidly in the U.S.(13)  Autism prevalence was recorded for U.K. 8-year-olds for the years 2004-2010; breastfeeding data that would apply to the years of the infancies of those children should therefore cover the years 1996 to 2002.  The closest years for which that data is available for the U.K. are 1995 to 2000.  According to the UK's National Health Service, breastfeeding prevalence past initial breastfeeding in the hospital did not increase between 1995 and 2000.17   After those years of stable breastfeeding, the first data point at which an increase is shown is 2005.  So, during the general period of the infancies of the U.K. children whose autism rates were not increasing, breastfeeding was basically level.


Since the increasing prevalence of autism reported in the U.S. between 2002 and 2008 also referred to 8-year-olds, the most relevant years of U.S. infant exposures to toxins would have been 1994 to 2000.  During that time interval, breastfeeding at 6 months in the U.S. increased 34%.18 Concentrations of developmental toxins in breast milk were also increasing, notably PBDEs, and especially in North America. (This probably related to the effect of California law requiring fire retardants in many household products.)  A study of sediment from multiple locations in the Great Lakes found an increase of PBDE levels by a factor of several hundred times since the 1970s, according to a 2007 report.19  PBDE concentrations in human milk in Canada were found to increase 7-fold between 1992 and 2002.20  Concentrations of that chemical in breast milk in North America rose to 10 to 100 times those in Europe.21  So, in contrast with the relatively stable breastfeeding rates and toxic exposures in the U.K. that preceded stable autism prevalence there, in the U.S. there was greatly increasing exposure to toxins in breast milk that preceded the large increase in autism in the U.S.


Message to health professionals and scientists reading this paper:  This author cordially invites you to indicate your reactions to the contents presented here.  As of now, new parents almost never hear anything but completely one-sided promotion of breastfeeding, with no mention of possible drawbacks except in cases of serious problems on the part of the mother.  If you feel that parents should be informed about both sides of this question and thereby enabled to make an educated decision in this important matter, please write to the author of this paper.  Also, if you find anything here that you feel isn't accurately drawn from trustworthy sources or based on sound reasoning, please by all means send your comments, to


Comments from readers:

From this paper's inception in early 2012 until present, the invitation has been extended to all readers to submit criticisms of the contents, asking them to point out how anything written here is not well supported by authoritative sources (as cited) or is not logically based on the evidence presented.  As of May 4, 2013, after more than a year, no criticisms of contents of this paper have yet been received in response to that invitation.  (That is significant, considering the thousands of visits we receive from readers every month.)  We have received some e-mails that have not criticized contents of this paper but which are of interest; several of those comments or inquiries and our responses to them are entered at  All comments are welcome, especially those that point out any deficiencies in our evidence in relation to conclusions drawn or any lack of quality in the reasoning as presented.  Please send comments or questions to .






 (3) CDC's Morbidity and Mortality Weekly Report  Weekly,   August 3, 2007 / Vol. 56 / No. 30  Breastfeeding Trends and Updated National Health Objectives for Exclusive Breastfeeding —United States, Birth Years 2000–2004p. 762, Table 2  at


(3a) U.S. EPA. Estimating Exposure To Dioxin-Like Compounds - Volume I: U.S. Environmental Protection Agency, Washington, D.C., EPA/600/8-88/005Ca., 2002, revised 2005 –, Section II.6, "Highly Exposed Populations" (nursing infants are considered to be one of the highly-exposed populations), 4/94 (p. 39) "Using these procedures and assuming that an infant breast feeds for one year, … the average daily dose to the infant over this period is predicted to be about 60 pg of TEQ/kg-d."

Also in section 4.3.5, at end of that section, "...the resulting RfD in standard units is 7 × 10−10 mg/kg-day." (that is, O.7 pg of TEQ/kg-d)   (RfD is the EPA’s estimate of a relatively safe dose).

For additional studies finding many-times higher exposure of breastfed infants than formula-fed infants to developmental toxins, see Section 1 at .

(3b)  Table 2 of Surgeon General's Call to Action to Support Breastfeeding 2011.  Also see Section 1.2.s.1.a of . 

(3c)  Surgeon General's Call to Action to Support Breastfeeding, 2011, Table 2; and Section D of 

(3d) Agency for Healthcare Research and Quality, U.S. DHHS, Systems to Rate the Strength of Scientific Evidence, Evidence Report/Technology Assessment: Number 47

(3e)  As reported to the U.S. Census Bureau, data for recent decades shows a very disproportionate number of male children with disabilities, especially mental impairment, with the gender ratio becoming more uneven among more recent births. This is evident in a National Academies Press publication. (TABLE 3-1 of  The Future of Disability in America,  Institute of Medicine (US) Committee on Disability in America; Field MJ, Jette AM, editors.  National Academies Press (US); 2007, found at   The U.S. Census Bureau’s question that was apparently used for obtaining this data asks, "Because of a physical, mental or emotional condition, does this person have serious difficulty concentrating, remembering, or making decisions?”  The percentage of males said to have such mental difficulties who were born since the early 1990’s is twice as high as the percentage of females in the same age group (that is, 5.2% for male children nationwide, which includes many of those with autism, vs. 2.6% of females); this is in sharp contrast with the apparently gender-equal numbers that apply to those born in the half-century leading up to the mid-1970’s.  And those born in the period between the mid-1970’s and the early 1990’s had an intermediate male-female disproportion of impairments.  This data is from U.S. Census Bureau Table B18104: SEX BY AGE BY COGNITIVE DISABILITY Universe: Civilian non-institutionalized population 5 years and over.  Data Set:  2008-2010 American Community Survey 3-Year Estimates (accessed Jan. 2012 at , using their search process)  The even ratio of mental disability among people born up to the mid-1970's, becoming very uneven later, is compatible with various studies, including finding that mortality is similar across genders; therefore the current gender equality among middle-aged and older people was that way from birth, not a result of more early deaths among retarded males.(Leonard et al. 2002; Gissler et al. 1999, as reported in Maulik PK, Harbour CK, 2011:  Epidemiology of Intellectual Disability. In: JH Stone, M Blouin, editors. International Encyclopedia of Rehabilitation. Available online: )  According to U.S. Dept. of Education IDEA data (Table 1-12: Children and students served under IDEA, Part B, in the U.S. and outlying areas, by gender and age group: Fall 1999 through fall 2008  at, the ratio of male to female children age 6-21 with disabilities in recent years has been 2 to 1, but among children 3 to 5 the ratio has been 7 to 3; this implies a ratio of impaired male to female children that has been growing still more uneven than the 2 to 1 ratio; remember that the 2-to-1 ratio was itself a dramatic change from gender equality a few decades earlier.   The above widens the scope of the uneven gender ratio of impairment beyond what is seen in the major increases in diagnosed cases of autism in recent decades.

(3f) Oxford Journals  Am. J. Epidemiol. (15 May 2005) 161 (10): 916-925. doi: 10.1093/aje/kwi123 Risk Factors for Autism: Perinatal Factors, Parental Psychiatric History, and Socioeconomic Status  Heidi Jeanet Larsson et al   J Child Psychol Psychiatry. 2005 Sep;46(9):963-71. Effects of familial risk factors and place of birth on the risk of autism: a nationwide register-based study. Lauritsen MB, et al.    Also  Rai D. et al. Parental socioeconomic status and risk of offspring autism spectrum disorders in a Swedish population-based study. JAACAP. 2012; 51: 467-476

(3g)   National Report on Human Exposure to Environmental Chemicals   Dioxin-Like Chemicals: Polychlorinated Dibenzo-p-dioxins, Polychlorinated Dibenzofurans, and Coplanar and Mono-ortho-substituted Polychlorinated Biphenyls   Centers for Disease Control and Prevention,  Atlanta, GA    Accessed at  Page updated April 2010    Also  Environmental Endocrine Disruption:  An Effects Assessment and Analysis, by Thomas Crisp et al, EPA,  in Environmental Health Perspectives, Vol. 106, Feb. 1998, Supplement. P.27. 

Also see Section 1.2.b.1 of

(4) see


(5) see


(6) see


(7) see


(8) see


(9) see


(10)  see


(11)   Durkin et al., Socioeconomic Inequality in the Prevalence of Autism Spectrum Disorder: Evidence from a U.S. Cross-Sectional Study,  PLoS One. 2010; 5(7): e11551 at, Tables 3.  And Croen LA, et al., Descriptive epidemiology of autism in a California population: who is at risk? J Autism Dev Disord. 2002;32(3):217–224.  Per Durkin et al., autism among children of high-SES families was found to be more prevalent than among children of low-SES families, in a ratio of 1.4 to 1 among U.S. whites but with an even higher ratio of 2.4 to 1 among blacks.   According to the CDC, the ratio of breastfeeding rates of college-graduate mothers compared with those of mothers who did not complete high school is high among U.S. whites (1.7 to 1), but with an even higher ratio among blacks (2 to 1). (Racial and Socioeconomic Disparities in Breastfeeding - United States., 2004 Table 1, at


Larsson et al., Risk factors for autism: perinatal factors, parental psychiatric history, and socioeconomic status.  Am J Epidemiol. 2005 May 15;  At  Lauritsen MB, et al.,  Effects of familial risk factors and place of birth on the risk of autism: a nationwide register-based study,  J Child Psychol Psychiatry. 2005 Sep;46(9):963-71.           Rai et al. Parental socioeconomic status and risk of offspring autism spectrum disorders in a Swedish population-based study. JAACAP. 2012; 51: 467-476


Table 5.1 of WHO’s Development of a Global Strategy on Infant and Young Child Feeding, WHO: EUR/01/5018050  E74173. at  This shows 99% and 98% rates of early breastfeeding in those countries.  With essentially all mothers breastfeeding except those with medical problems, there is not sufficient population of non-breastfeeders to comprise a socio-economic group who breastfeed less than high-SES mothers.


Durkin MS et al., Childhood cognitive disability. In: Wallace RB, editor. Hightstown, NJ: McGraw-Hill; 2007. pp. 1173–1184. Public health and preventive medicine, fifteenth edition.


13) Taylor et al., Prevalence and incidence rates of autism in the UK: time trend from 2004–2010 in children aged 8 years.  BMJ Open  2013;3:e003219. doi:10.1136/bmjopen-2013-003219 at


17) , Ch. 2, p.13


18) CDC’s 2011 Pediatric Nutrition Surveillance, National Summary of Trends in Breastfeeding, Table 13D, at


19)   Sec. II.B of Brominated Flame Retardants, Third annual report to the Maine Legislature, 2007, D Rice et al., citing Li et al., 2005a


(A copy of this statement, with working links to most of the references, in PDF format, is at

20)   Table 3 of Developmental Neurotoxicity of Polybrominated Diphenyl Ether (PBDE) Flame Retardants, Costa et al., Neurotoxicology. 2007 November; 28(6):   NIHMS34875 at

21) Schecter A et al., Polybrominated diphenyl ethers (PBDEs) in U.S. mothers' milk.  Environ Health Perspect. 2003 Nov;111(14):1723-9