List of Environmental Factors that affect IQ

Neurobiological Theory


Neurobiological theory tells us that the development of a humans various forms of intelligence usually ends by the age of 16, when a criticial point is reaches. Afrer this point of intellectual maturity, IQ is thought to be relatively stable. The environment has its biggest affect in determining someone's fluid intelligence up and till the critical point. Fluid Intelligence is someone's ability to think logically in verbal and spatial terms and detect patterns too.

For a person to develop certain intellectual abilities, they need to be provided with the appropriate environmental stimuli during childhood, before the critical period for adapting their neuronal connections ends. It should be mentioned that some researchers believe that the critical period effect is a result of the manner by which intellectual abilities are acquired—that changes in neuronal connections inhibit or prevent possible future changes which may explain differences in Intelligence types between people of different cultures.

Environmental Factors that affect IQ include: modern media, education, breast feeding, womb conditions, butrition, pollution, nurture and parenting, prejudices and self belief, national culture, head injuries, sleep problems, drug and alcohol abuse, mental illnesses, stress and diseases.


Modern Media

Modern Media forms including TV, film, computer games, electronic gadgets and devices, the Internet and computer software are giving people a cognitive work out each time they participate in these forms of modern media. Computer games, software and gadgets require great analytical and logical thought and probing in order to be used to their entirety.(*4)

Television shows are becoming more complex with up to 18 threads happening at once often spreading over mutliple episodes are re-appearing at different times, compared to just 1 50 years ago. The viewer is required to keep track of many threads at once. It is also becoming harder to make sense of what is actually happening on the screen which as peoples analytical skills and pattern recognition skills are being pushed.(*4)


Education

Increasing the time in educaton and quality of education before the critical limit and to a lesser extent afterwards, has been shown to improve a person's performance on an intelligence test.


Breast Feeding

In a comprehensive study involving 11 studies and ouver 7000 children, children who were breast fed were found to do 5.2 points better on IQ tests than children who were not breastfed.

http://www.breastfeeding.com/reading_room/iq_study.html


Womb Conditions

High intakes of alchohol and drug use in mothers have been shown to significantly lower the IQ of their children.(*2) Extent of prenatal exposure to marijuana affects development of intelligence later in childhood.(*3)

Prolonged period of time without access to oxygen during the delivery can lead to brain damage and mental retardation. Also, low birth weights have been linked to lower intelligence scores later in lives of the children.

http://www.upmc.com/Communications/MediaRelations/Research/Articles/AlcoholLowersIQ.htm


Nutrition

Poor nutrition, characterized by zinc, iron, vitamin B and protein deficiencies, leads to low IQ, which leads to later antisocial behavior.

http://www.scienceagogo.com/news/20041021205759data_trunc_sys.shtml
http://www.healingwithnutrition.com/adisease/add-adhd/harrellstudy.html


Pollution

Lead exposure has been proven to have significant effects on the develpment of a child's intelligence. In a long-term study done by Baghurst et al. 1992, children who grew up next to a lead-smelting plant had significantly lower intelligence test scores, negatively correlated with their blood-lead level exposure.(*2)

http://www.msnbc.msn.com/id/23188393/
http://www.niehs.nih.gov/research/supported/sep/2008/loweriq.cfm


Nurture and Parenting

Forster Care boosts an Orphan's IQ. Children who left an Orphanage before the age of 2 saw an almost 15 point increase in IQ over a 2.5 year period compared to children who stayed behind.

http://www.sptimes.com/2007/12/21/Worldandnation/Study__Foster_care_bo.shtml


Prejudices and Self Belief

Women who did a math test scored 10-15% worse when they had to tick a box describing their gender before the test than women who didnt have to tick a box describing their gender before the test.

http://lifeandhealth.guardian.co.uk/wellbeing/story/0,,2275833,00.html


National Culture

Japanese people have a culture which uses more sociable thinking, whereas american culture uses more independant thinking.

Native Japanese people used a different part of the brain to solve the same spatial problem as american japanese and americans. The Native japanese solved the problem fastest, significantly.

http://www.sciencedaily.com/releases/2008/01/080111102934.htm
http://www.livescience.com/health/080118-culture-brain.html


Head Injuries

Head injuries, particularly to the occipital and pareital Lobes at the back of the head lower the IQ depending on the severity of the head injury and the medical treatment afterwards.
http://www.braininjury.com/children.html


Sleep Problems

Children with sleep apnea scored an average IQ of 85 while children without sleep apnea scored an average IQ of 101
http://www.disabled-world.com/artman/publish/article_1120.shtml
http://help-me-to-sleep.com/sleep-apnea/sleep-apnea-and-child-iq-scores.html


Drug and Alcohol Abuse

Cocaine exposure to children has been shown to sublty (but statistically significantly) lower a child's IQ and language skills.

http://www.sciencemag.org/cgi/content/summary/282/5389/633


Mental Illnesses

Men with below average IQ scores has a 40% greater risk of developing schizophrenia
http://www.schizophrenia.com/sznews/archives/000607.html

Schizophrenic patients were found to have below average processing speeds when performing IQ tests but still got the same number of questions right on average as non schizophrenics.

http://www.blackwell-synergy.com/doi/abs/10.1034/j.1601-5215.2002.140302.x?cookieSet=1&journalCode=acn


Stress

Children who are emotional or physical stress score 13% lower on IQ tests than children who are not.

http://query.nytimes.com/gst/fullpage.html?sec=health&res=9802E3DE163BF932A05756C0A965948260&fta=y


Diseases

Multiple Sclerosis can lower a child's IQ.
http://www.medicalnewstoday.com/articles/107185.php

Malaria affects 300–500 million persons each year, mostly children under age five in Africa, causses widespread anemia during a period of rapid brain development and also direct brain damage from cerebral malaria to which children are more vulnerable.

http://www.ncbi.nlm.nih.gov/pubmed/12394524?dopt=Citation



BOOK REFERENCES

(*2)Neisser, U.; Boodoo, G.; Bouchard Jr, T.J.; Boykin, A.W.; Brody, N.; Ceci, S.J.; Halpern, D.F.; Loehlin, J.C.; Perloff, R.; Sternberg, R.J.; Others, (1998). "Intelligence: Knowns and Unknowns". Annual Progress in Child Psychiatry and Child Development 1997. Retrieved on 2008-03-18

(*3)Pulsifer MB, Butz AM, O'Reilly Foran M, Belcher HM. Prenatal drug exposure: effects on cognitive functioning at 5 years of age. Clinical Pediatrics. 2008 Jan;47(1):58-65.

(*4)Everything Bad Is Good for You: by Steven Berlin Johnson.