|Intelligence: intelligence is the ability to recognize patterns in presented information or to recognize possibilities for supplementing and transforming known patterns that go beyond repetitions._____________Annotation: The above characterizations of concepts are neither definitions nor exhausting presentations of problems related to them. Instead, they are intended to give a short introduction to the contributions below. – Lexicon of Arguments. |
|Slater I 126
Intelligence/molecular genetics: Though there is still  considerable debate about the magnitude of the heritability, the presence of substantial genetic influence is now well established, through the accumulation of evidence from many studies in many different samples (see Deary, Johnson, & Houlihan, 2009(1), for a recent review, and Neisser et al., 1996(2), for the consensus statement of an American Psychological Association Task Force).
In contrast to the view prevailing at the time Jensen wrote (see Jensen 1969(2), >Intelligence/Jensen, >Intelligence tests/Jensen, >Heritability/Jensen, >Intelligence tests/psychological theories), the existence of genetic influences on behavioural traits of all kinds is now generally accepted (Turkheimer, 2000)(3), which means that it would be considered exceptional if intelligence and achievement test scores were not genetically influenced.
Slater I 127
Genome-wide association studies of cognitive ability test scores have yielded many alleles of extremely small effects that tend not to replicate from sample to sample and account at best for only tiny proportions of trait variance. At present we have not yet identified a single gene locus robustly associated with normal range cognitive ability test scores (Davis, Butcher, Docherty, Meaburn, & Curtis, 2010(4); Deary, Penke, & Johnson, 2010)(5). The general failure to identify clear associations between particular gene loci and highly heritable, well-measured common traits has been termed the “missing heritability problem” (Maher, 2008)(6). [There are] more complex genetic mechanisms (see Johnson, Penke, & Spinath, 2011(7), for more detailed information).
1. Deary, I. J., Johnson, W., & Houlihan, L. (2009). Genetic foundations of human intelligence. Human Genetics, 126, 613–624.
2. Neisser, U., Boodoo, G., Bouchard, T. J., Boykin, A. W., Brody, N., Ceci, S. J., Halpern, D. F., Loehlin, J. C., Perloff, R., Sternberg, R. J., & Urbina, S. (1996). Intelligence: Knowns and unknowns. American Psychologist, 51, 77–101.
3. Turkheimer, E. (2000). Three laws of behavior genetics and what they mean. Current Directions in Psychological Science, 9, 160–164.
4. Davis, O. S., Butcher, L. M., Docherty, S. J., Meaburn, E. L., & Curtis, C. J. (2010). A three-stage genome-wide association study of general cognitive ability: Hunting the small effects. Behavior Genetics, 40, 759–767.
5. Deary, I. J., Penke, L., & Johnson, W. (2010). The neuroscience of human intelligence differences. Nature Reviews Neuroscience, 11, 201–211.
6. Maher, B. (2008). The case of the missing heritaiblity. Nature, 456, 18–21.
7. Johnson, W., Penke, L., & Spinath, F. M. (2011). Heritability in the era of molecular genetics. European Journal of Personality, 25, 254–266.
Wendy Johnson: „How Much Can We Boost IQ? Updated Look at Jensen’s (1969) Question and Answer“, in: Alan M. Slater & Paul C. Quinn (eds.) 2012. Developmental Psychology. Revisiting the Classic Studies. London: Sage Publications_____________Explanation of symbols: Roman numerals indicate the source, arabic numerals indicate the page number. The corresponding books are indicated on the right hand side. ((s)…): Comment by the sender of the contribution. The note [Author1]Vs[Author2] or [Author]Vs[term] is an addition from the Dictionary of Arguments. If a German edition is specified, the page numbers refer to this edition.
Alan M. Slater
Paul C. Quinn
Developmental Psychology. Revisiting the Classic Studies London 2012