What are the factors that influence intelligence

Factors Affecting Intelligence

1) Heredity and Environment:

Heredity provided the physical body to be developed with certain inherent capabilities while environment provides for the maturation and training of the organism. In 1940 Newman concluded that variations in I.Q. were determined about 68% by heredity and 32% by environment.

During an individual’s life time variation in I.Q. is due to environment, since the heredity cannot change. Improved nutrition health, an stimulus situations would account for this change. Environment of children ages 2 to 4 years appears to be critical since the child normally learns language at this time. Better homes, school, medical facilities, less economic discrimination. Provides a mean for achieving a mentally able population.

2) Age:

A person who bright or dull in childhood tends to remain bright or dull throughout his life. Growth I intelligence can continue through the early twenties, person achieves his maximum 10 at about 20 years are and remain stable till 10 years and decreases after that. Some abilities remain constant while others decline rapidly due to decline in physical efficiency. It is observed that the more intelligent person has more rapid of mental growth and continues to develop longer than does the mentally less able.

3) Race and Nationality:

There is no prominent evidence to show that race in a factor for determining intellectual level. Difference exist between families are due to environment. The differences in races are also due to opportunity for training in early years.

All evidence indicates that there is little or no difference in inherited intellectual capacity due to race. There are differences, mostly due to opportunities for training and learning. The idea of inferior races due to heredity is not true.

4) Culture:

 Answer in intelligent test question are highly cultural. Cultural will determine the degree of a person’s attitude and abilities.

5) Health and Physical Development:

Physical and mental health is related to one’s ability to gain desired achievement. A mental activity with delicate health, one may not possess enough energy to engage in mental activity to the extent that he achieves success. Physical defects such as in complete maturation of brain cells sensory and physical handicaps many interfere with observable intelligent behavior. Diseases also affect intelligence. Emotional bodies may interferes one’s ability. Unfavorable health affects mental status of the individual.

6) Sex:

It is a popular belief that boys are suppose to be more intelligent than girls. The research studies have shown that there is no significant differences between the sexes, on the average, girls seems to show slight superiority in language, memory and appreciation. Differences in intelligence are caused partly by environmental conditions

7) Social and Economic Conditions:

Home plays a significance role in the early developmental years. Home conditions influence on behaviours attitude. The financial status or the parents, neighborhood and environmental conditions also affect on the intelligence but due to their soci-economic status.

Mentally defective, People (Feeble – minded): Individuals whose I.Q.’s are below 70 they are called as mentally defective or feeble – minded people. They suffer from mamentia or luck of mind. Ladiecy-It is lowest grade of

1. Gottfredson LS. Mainstream science on intelligence: An editorial with 52 signatories, history, and bibliography. Intelligence. 1997;24:13–23. [Google Scholar]

2. Nisbett RE, Aronson J, Blair C, Dickens W, Flynn J, Halpern DF, et al. Intelligence: New findings and theoretical developments. Am Psychol. 2012;67:130–59. [PubMed] [Google Scholar]

3. DiLalla LF. Development of intelligence: Current research and theories. J Sch Psychol. 2000;38:3–7. [Google Scholar]

4. Davies G, Tenesa A, Payton A, Yang J, Harris SE, Liewald D, et al. Genome-wide association studies establish that human intelligence is highly heritable and polygenic. Mol Psychiatry. 2011;16:996–1005. [PMC free article] [PubMed] [Google Scholar]

5. Galton F. The history of twins, as a criterion of the relative powers of nature and nurture (1,2) Int J Epidemiol. 2012;41:905–11. [PubMed] [Google Scholar]

6. Der G, Batty GD, Deary IJ. Effect of breast feeding on intelligence in children: Prospective study, sibling pairs analysis, and meta-analysis. BMJ. 2006;333:945. [PMC free article] [PubMed] [Google Scholar]

7. More S, Shivkumar VB, Gangane N, Shende S. Effects of iron deficiency on cognitive function in school going adolescent females in rural area of central India. Anemia. 2013;2013:819136. [PMC free article] [PubMed] [Google Scholar]

8. Conklin SM, Gianaros PJ, Brown SM, Yao JK, Hariri AR, Manuck SB, et al. Long-chain omega-3 fatty acid intake is associated positively with corticolimbic gray matter volume in healthy adults. Neurosci Lett. 2007;421:209–12. [PubMed] [Google Scholar]

9. Warsito O, Khomsan A, Hernawati N, Anwar F. Relationship between nutritional status, psychosocial stimulation, and cognitive development in preschool children in Indonesia. Nutr Res Pract. 2012;6:451–7. [PMC free article] [PubMed] [Google Scholar]

10. Dubow EF, Boxer P, Huesmann LR. Long-term effects of parents' education on children's educational and occupational success: Mediation by family interactions, child aggression, and teenage aspirations. Merrill Palmer Q (Wayne State Univ Press) 2009;55:224–49. [PMC free article] [PubMed] [Google Scholar]

11. Maurin E. The impact of parental income on early schooling transitions: A re-examination using data over three generations. J Public Econ. 2002;85:301–32. [Google Scholar]

12. Baghurst PA, McMichael AJ, Wigg NR, Vimpani GV, Robertson EF, Roberts RJ, et al. Environmental exposure to lead and children's intelligence at the age of seven years. The Port Pirie Cohort Study. N Engl J Med. 1992;327:1279–84. [PubMed] [Google Scholar]

13. Wasserman GA, Liu X, Lolacono NJ, Factor-Litvak P, Kline JK, Popovac D, et al. Lead exposure and intelligence in 7-year-old children: The Yugoslavia Prospective Study. Environ Health Perspect. 1997;105:956–62. [PMC free article] [PubMed] [Google Scholar]

14. Neisser U, Boodoo G, Bouchard TJ, Jr, Boykin AW, Brody N, Ceci SJ, et al. Intelligence: Knowns and unknowns. Am Psychol. 1996;51:77–100. [Google Scholar]

15. índer A, Gülay H. Reliability and validity of parenting styles & dimensions questionnaire. Procedia Soc Behav Sci. 2009;1:508–14. [Google Scholar]

16. Sameroff AJ, Seifer R, Baldwin A, Baldwin C. Stability of intelligence from preschool to adolescence: The influence of social and family risk factors. Child Dev. 1993;64:80–97. [PubMed] [Google Scholar]

17. Black SE, Devereux PJ, Salvanes KG. Small family, smart family. Family size and the IQ scores of young men? J Hum Res. 2010;45:33–58. [Google Scholar]

18. Retherford RD, Sewell WH. Intelligence and family size reconsidered. Soc Biol. 1988;35:1–40. [PubMed] [Google Scholar]

19. Ceci SJ. How much does schooling influence general intelligence and its cognitive components. A reassessment of the evidence? Dev Psychol. 1991;27:703–22. [Google Scholar]

20. Tomporowski PD, Davis CL, Miller PH, Naglieri JA. Exercise and children's intelligence, cognition, and academic achievement. Educ Psychol Rev. 2008;20:111–31. [PMC free article] [PubMed] [Google Scholar]

21. O'Dea JW. The Effect of Extra-curricular Activities on Academic Achievement (Doctoral Dissertation, Drake University) 1994 [Google Scholar]

22. Lekies KS, Cochran M. Collaborating for Kids. New York State Universal Prekindergarten 1999-2000 [Google Scholar]


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Demographic details of students (n=1065)

What are the factors that influence intelligence