この研究はIQの高さが良い生活習慣や経済状態などをもたらす結果として心臓病リスクを下げているというだけでは、とどまっていない。
Why would low I.Q. predict heart risk? Researchers pose a number of theories. It may be that some of the factors in early life that lead to low I.Q. may also lead to poorer heart health.Dr. GD Battyの目指すは、高い知能と健康の直接的関係を示すことらしい。
なぜIQが低いと心臓のリスクが高いのか？研究者は幾つかの理論を提示している。IQを低くしている若いころの要因の幾つかが、心臓の健康にも悪い影響を与えているかもしれない。
“I.Q. is a marker of lifetime insults, physiological insults,’’ said David Batty, a Wellcome Trust fellow and scientist at the Medical Research Council in Glasgow, the U.K. government’s national health research agency. ”We know kids with poor diets, kids who have repeated infections, have a lower I.Q., so it could be an I.Q. is capturing something about lifelong misery.’’
「IQは人生の傷跡、生理学的な傷跡である。食事の貧しい子どもや、感染症に繰り返し罹った子どものIQが低いことが分かっている。したがって、IQは生涯にわたる不幸の何らかの指標になっているかもしれない」と英国政府の健康研究機関であるグラスゴーのMedical Research CouncilのWellcome Trust fellowであるDavid Battyは言う。
People with lower intelligence also are known to adopt less healthful behaviors ― they smoke and drink more and are more likely to have a poor diet. It may be that people with low I.Q. have a more difficult time understanding complex health messages and don’t fully understand the long-term health effects of an unhealthy lifestyle.
知能の低い人は健康的な習慣をとらない傾向があることがわかっている。彼らは煙草を吸って、酒を飲んで、食事が貧しくなる傾向がある。IQが低いと複雑な健康情報を理解するのが困難で、長期にわたる健康への不健康なライフスタイルによる影響を完全には理解できない。
The U.K. researchers have also posed a provocative theory that a high I.Q. is not just a marker for a better education, higher income and overall better life circumstances. It may also be that a high I.Q. is associated with better overall neurological and physiological “wiring,’’ meaning all the body systems, from brain to heart to liver to kidneys, function at a more efficient level.
英国の研究者たちはまた、IQが高いことは良い教育・高い収入・全般的な良い生活環境だけの指標ではないという挑発的な理論を提示している。高いIQは、神経系および生理系の"接続"すなわち、脳から心臓から肝臓から腎臓まで、全身について、より効率的に機能していることと関連しているかもしれない。
[TARA PARKER-POPE: "Low I.Q. Predicts Heart Disease" (2010/02/10) on Well - Tra Parker-Pope on Health on New York Times]
ということで、Dr. GD Battyは知能と健康の関係をえんえんと研究対象としている：
- 子どもの頃に自制心が強さが成人後の健康を守る
Gale, GD Batty and Ian: "Locus of Control at Age 10 Years and Health Outcomes and Behaviors at Age 30 Years: The 1970 British Cohort Study", Psychosomatic Medicine 70:397?403 (2008)
Objective: To examine the relationship between locus of control at age 10 years and self-reported health outcomes (overweight, obesity, psychological distress, health, and hypertension) and health behaviors (smoking and physical activity) at age 30, controlling for sex, childhood IQ, educational attainment, earnings, and socioeconomic position.
Methods: Participants were members of the 1970 British Cohort Study, a national birth cohort. At age 10, 11,563 children took tests to measure locus of control and IQ. At age 30, 7551 men and women (65%) were interviewed about their health and completed a questionnaire about psychiatric morbidity.
Results: Men and women with a more internal locus of control score in childhood had a reduced risk of obesity (odds ratio, 95% CI, for a SD increase in locus of control, 0.86, 0.78?0.95), overweight (0.87, 0.82? 0.93), fair or poor self-rated health (0.89, 0.81? 0.97), and psychological distress (0.86, 0.76?0.95). Women with a more internal locus of control had a reduced risk of high blood pressure (0.84, 0.76?0.92). Associations between childhood IQ and risk of obesity and overweight were weakened by adjustment for internal locus of control.
Conclusion: Having a stronger sense of control over one’s own life in childhood seems to be a protective factor for some aspects of health in adult life. Sense of control provides predictive power beyond contemporaneously assessed IQ and may partially mediate the association between higher IQ in childhood and later risk of obesity and overweight. Key words: personality, intelligence, health outcomes, health behaviors, control beliefs. - 男性について、成人初期のIQが高いと、中年での全死亡率および事故死亡率が小さい
G. David Batty et al: "IQ in Early Adulthood and Mortality By Middle Age Cohort Study of 1 Million Swedish Men", Epidemiology 2009;20: 100?109
Background: High premorbid IQ test scores are related to a reduced rate of later total mortality, although little is known about the shape of this association (ie, dose-response versus threshold), or the role of mediating and confounding factors in explaining it. Additionally, the link between IQ and causespecific
mortality has been little explored.
Methods: A cohort of over 1 million Swedish men who underwent IQ testing at military service conscription at about 18 years of age was followed for mortality experience until middle age.
Results: An average of 20 years of follow-up gave rise to 14,498 deaths in an analytical sample of 994,262. In basic analyses adjusting for age, year of birth, and conscription testing center, lower IQ scores were associated with an elevated risk of all-cause mortality (HR per 1-SD decrease in IQ; 1.32; 95% confidence interval 1.30 ?1.34). This relation was incremental across the full IQ range, and was robust to adjustment for indicators of childhood social circumstances. The association did not appear to be mediated by factors measured concurrent with IQ (blood pressure, body mass index, or cigarette smoking), nor was it attributable to reverse causality. However, controlling for education (a close correlate of IQ) led to marked attenuation. IQ was also associated with mortality from accidents, coronary heart disease, and suicides, but not cancer.
Conclusions: In this large cohort we found a robust stepwise relation between early adult IQ and risk of total and accident mortality in men. - 男性について、成人初期のIQが高いと、殺人による死亡リスクが小さい
GD Batty et al:"IQ in early adulthood and later risk of death by homicide: cohort study of 1 million men", IQ in early adulthood and later risk of death by homicide: cohort study of 1 million men
Background:
Risk factors for homicide are emerging; however, the predictive value of IQ, for which there is a strong prima facie case, has yet to be examined.
Aims:
To examine the association between IQ and risk of death by homicide.
Method:
A cohort of 968 846 men, aged 18?19 years, were administered an IQ test battery at military conscription and then followed for mortality experience over two decades.
Results:
There were 191 deaths due to homicide during follow-up. In age-adjusted analyses, a high total IQ test score was associated with a reduced rate of homicide (hazard ratio (HR) per standard deviation increase in IQ score=0.49, 95% CI 0.42?0.57). A step-wise gradient was apparent across the three IQ groups (P-value for trend <0.001). After adjustment for indicators of socio-economic position and illness at conscription, this gradient was marginally attenuated (HR=0.57, 95% CI 0.49?0.67).
Conclusions:
High IQ test scores in early adulthood were associated with a reduced risk of death by homicide. - 男性についての成年期後期から成人初期のIQが高いと、中年のリスク要因と高年の冠疾患死亡率が
GD Batty et al:"IQ in late adolescence/early adulthood, risk factors in middle-age and later coronary heart disease mortality in men: the Vietnam Experience Study", Eur J Cardiovasc Prev Rehabil 15:359?361 c 2008
Objective: Examine the relation between IQ in early adulthood and later coronary heart disease (CHD) mortality, and assess the extent to which established risk factors measured in middle-age might explain this gradient.
Design: Cohort study of 4316 male former Vietnam-era US army personnel with IQ scores (mean age 20.4 years), risk factor data (mean age 38.3 years) and 15 years mortality surveillance.
Results: In age-adjusted analyses, lower IQ scores were associated with an increased rate of CHD mortality (hazard ratio per SD decrease in IQ; 95% confidence interval: 1.34; 1.00, 1.79). Adjustment for later chronic disease (1.22; 0.91, 1.64), behavioural (1.29; 0.95, 1.74) and physiological risk factors (1.19; 0.88, 1.62) led to some attenuation of this gradient. This attenuation was particularly pronounced on adding socioeconomic indices to the multivariable model when the IQ?CHD relation was eliminated (1.05; 0.73, 1.52). A similar pattern of association was apparent when cardiovascular disease was the outcome of interest.
Conclusion: High IQ may lead to educational success, well remunerated and higher prestige employment, and
this pathway may confer cardio-protection. - 子どものときの知能と冠疾患および脳卒中の関係
Lawlor and GD Batty: "Association of childhood intelligence with risk coronary heart disease and stroke: findings from the Aberdeen Chidren of the 1950s cohort study. Eur J Epidemiol, DOI 10.1007/s10654-008-9281-z
Conclusions: Our results suggest an association of intelligence in childhood with future CHD and stroke that is unlikely to be explained by reverse causality and was robust to adjustment for a wide range of confounding factors. This association appeared to be mediated by educational attainment. The gender defference seen in out study requires replication in other studies.
