How early in development do promising signs for differing forms of eminence emerge? Given the eve... more How early in development do promising signs for differing forms of eminence emerge? Given the ever-increasing emphasis on human capital in our conceptual economy and the importance of staying economically competitive in a "flat world" (Friedman, 2007; Rindermann & Thompson, 2011; Zakaria, 2011), this question has implications beyond a theoretical understanding of how exceptional careers develop (Lubinski & Benbow, 2000; Murray, 2003; Simonton, 2014). Studies of intellectually precocious youth have already revealed that assessing the level and pattern of abilities within the top 1% (which constitutes over one third of the ability range) is critical for understanding contrasting creative accomplishments and high-impact careers (Lubinski, 2016; Makel, Kell, Lubinski, Putallaz, & Benbow, 2016). More ability matters, as does the ability pattern. The former is related to the magnitude of accomplishment, whereas the latter is related to the nature of the fields pursued. In addition, information regarding personal preferences is also essential to accurately model the unfolding of exceptional careers that maintain and advance modern cultures. This investigation examined the extent to which two distinct ability and preference constellations (math/ scientific and verbal/humanistic) assessed at age 13 in intellectually precocious youth predict distinct forms of eminence 35 years later. In past research with intellectually precocious 13-year-olds, Achter, Lubinski, Benbow, and Eftekhari-Sanjani (1999) showed that psychometric assessments of abilities and preferences each add value to the prediction of concrete educational outcomes 10 years later. Subsequently, Wai, Lubinski, and Benbow (2005) successfully used the math/scientific 822524P SSXXX10.
Reported is the 20-year follow-up of 1,975 mathematically gifted adolescents (top 1%) whose asses... more Reported is the 20-year follow-up of 1,975 mathematically gifted adolescents (top 1%) whose assessments at age 12 to 14 revealed robust gender differences in mathematical reasoning ability. Both sexes became exceptional achievers and perceived themselves as such; they reported uniformly high levels of degree attainment and satisfaction with both their career direction and their overall success. The earlier sex differences in mathematical reasoning ability did predict differential educational and occupational outcomes. The observed differences also appeared to be a function of sex differences in preferences for (a) inorganic versus organic disciplines and (b) a career-focused versus more-balanced life. Because profile differences in abilities and preferences are longitudinally stable, males probably will remain more represented in some disciplines, whereas females are likely to remain more represented in others. These data have policy implications for higher education and the world of work.
Although much genetic research has addressed normal variation in intelligence, little is known ab... more Although much genetic research has addressed normal variation in intelligence, little is known about the etiology of high cognitive abilities. Using data from 11,000 twin pairs (age range = 6-71 years) from the Genetics of High Cognitive Abilities (GHCA) Consortium, we investigated the genetic and environmental etiologies of high general cognitive ability (g). Age-appropriate psychometric cognitive tests were administered to the twins and used to create g scores standardized within each study. Liability-threshold model fitting was used to estimate genetic and environmental parameters for the top 15% of the distribution of g. Genetic influence for high g was substantial (0.50, with a 95% confidence interval of 0.41-0.60). Shared environmental influences were moderate (0.28, 0.19-0.37). We conclude that genetic variation contributes substantially to high g in Australia, the Netherlands, the United Kingdom and the United States.
A sample of 1,586 intellectually talented adolescents (top 1%) were assessed on the math portion ... more A sample of 1,586 intellectually talented adolescents (top 1%) were assessed on the math portion of the SAT by age 13 and tracked for more than 25 years. Patents and scientific publications were used as criteria for scientific and technological accomplishment. Participants were categorized according to whether their terminal degree was a bachelor's, master's, or doctorate degree, and within these degree groupings, the proportion of participants with at least one patent or scientific publication in adulthood increased as a function of this early SAT assessment. Information about individual differences in cognitive ability (even when measured in early adolescence) can predict differential creative potential in science and technology within populations that have advanced educational degrees.
There is increasing evidence for the role of rare copy-number variation (CNV) in the development ... more There is increasing evidence for the role of rare copy-number variation (CNV) in the development of neuropsychiatric disorders. It is likely that such variants also have an effect on the variation of cognition in what is considered the ''normal'' phenotypic range. The role of rare CNV ([20 KB in length; frequency \5 %) on general cognitive ability is investigated in a sample of 800 individuals (mean age = 16.5, SD = 1.2) using copy-number variants called from the Illumina 610K SNP genotyping array with the software Quanti-SNP. We assessed three measures of CNV burden-total CNV length, number of CNV and average CNV length-for both deletions and duplications in combination and separately. No correlation was found between any of the measures of CNV burden and IQ, or when comparing the top and bottom 10 % of the sample for IQ, both on a genome-wide scale and at individual positions across the genome.
Students identified by talent search programs were studied to determine whether spatial ability c... more Students identified by talent search programs were studied to determine whether spatial ability could uncover math-science promise. In Phase 1, interests and values of intellectually talented adolescents (617 boys, 443 girls) were compared with those of top math-science graduate students (368 men, 346 women) as a function of their standing on spatial visualization to assess their potential fit with math-science careers. In Phase 2, 5-year longitudinal analyses revealed that spatial ability coalesces with a constellation of personal preferences indicative of fit for pursuing scientific careers and adds incremental validity beyond preferences in predicting mathscience criteria. In Phase 3, data from participants with Scholastic Aptitude Test (SAT) scores were analyzed longitudinally, and a salient math-science constellation again emerged (with which spatial ability and SAT-Math were consistently positively correlated and SAT-Verbal was negatively correlated). Results across the 3 phases triangulate to suggest that adding spatial ability to talent search identification procedures (currently restricted to mathematical and verbal ability) could uncover a neglected pool of math-science talent and holds promise for refining our understanding of intellectually talented youth.
This longitudinal study tracked 1,110 adolescents identified as mathematically precocious at Age ... more This longitudinal study tracked 1,110 adolescents identified as mathematically precocious at Age 13 (top 1%) with plans for a math-science undergraduate major. Participants' high school educational experiences, abilities, and interests predicted whether their attained undergraduate degrees were within math-science or nonmath-nonscience areas. More women than men eventually completed undergraduate degrees outside math-science, but many individuals who completed nonmath-nonscience degrees ultimately chose math-science occupations (and vice versa). At Age 33, the 2 degree groups reported commensurate and uniformly high levels of career satisfaction, success, and life satisfaction. Assessing individual differences is critical for modeling talent development and life satisfaction; it reveals that equal male-female representation across disciplines may not be as simple to accomplish as many policy discussions imply. The male-female disparity in math and science is well documented and is particularly apparent at rising levels along the educational-vocational continuum ( Lane
Talent-search participants (286 males, 94 females) scoring in the top 0.01% on cognitive-ability ... more Talent-search participants (286 males, 94 females) scoring in the top 0.01% on cognitive-ability measures were identified before age 13 and tracked over 20 years. Their creative, occupational, and life accomplishments are compared with those of graduate students (299 males, 287 females) enrolled in top-ranked U.S. mathematics, engineering, and physical science programs in 1992 and tracked over 10 years. By their mid-30s, the two groups achieved comparable and exceptional success (e.g., securing top tenure-track positions) and reported high and commensurate career and life satisfaction. College entrance exams administered to intellectually precocious youth uncover extraordinary potential for careers requiring creativity and scientific and technological innovation in the information age.
Journal of Personality and Social Psychology, 2009
Work preferences, life values, and personal views of top math/science graduate students (275 men,... more Work preferences, life values, and personal views of top math/science graduate students (275 men, 255 women) were assessed at ages 25 and 35 years. In Study 1, analyses of work preferences revealed developmental changes and gender differences in priorities: Some gender differences increased over time and increased more among parents than among childless participants, seemingly because the mothers' priorities changed. In Study 2, gender differences in the graduate students' life values and personal views at age 35 were compared with those of profoundly gifted participants (top 1 in 10,000, identified by age 13 and tracked for 20 years: 265 men, 84 women). Again, gender differences were larger among parents. Across both cohorts, men appeared to assume a more agentic, career-focused perspective than women did, placing more importance on creating high-impact products, receiving compensation, taking risks, and gaining recognition as the best in their fields. Women appeared to favor a more communal, holistic perspective, emphasizing community, family, friendships, and less time devoted to career. Gender differences in life priorities, which intensify during parenthood, anticipated differential male-female representation in high-level and timeintensive careers, even among talented men and women with similar profiles of abilities, vocational interests, and educational experiences.
We used a case-control genome-wide association (GWA) design with cases consisting of 1238 individ... more We used a case-control genome-wide association (GWA) design with cases consisting of 1238 individuals from the top 0.0003 (~170 mean IQ) of the population distribution of intelligence and 8172 unselected population-based controls. The single-nucleotide polymorphism heritability for the extreme IQ trait was 0.33 (0.02), which is the highest so far for a cognitive phenotype, and significant genome-wide genetic correlations of 0.78 were observed with educational attainment and 0.86 with population IQ. Three variants in locus ADAM12 achieved genome-wide significance, although they did not replicate with published GWA analyses of normal-range IQ or educational attainment. A genome-wide polygenic score constructed from the GWA results accounted for 1.6% of the variance of intelligence in the normal range in an unselected sample of 3414 individuals, which is comparable to the variance explained by GWA studies of intelligence with substantially larger sample sizes. The gene family plexins, members of which are mutated in several monogenic neurodevelopmental disorders, was significantly enriched for associations with high IQ. This study shows the utility of extreme trait selection for genetic study of intelligence and suggests that extremely high intelligence is continuous genetically with normal-range intelligence in the population.
Although individual differences in intelligence (general cognitive ability) are highly heritable,... more Although individual differences in intelligence (general cognitive ability) are highly heritable, molecular genetic analyses to date have had limited success in identifying specific loci responsible for its heritability. This study is the first to investigate exome variation in individuals of extremely high intelligence. Under the quantitative genetic model, sampling from the high extreme of the distribution should provide increased power to detect associations. We therefore performed a case–control association analysis with 1409 individuals drawn from the top 0.0003 (IQ >170) of the population distribution of intelligence and 3253 unselected population-based controls. Our analysis focused on putative functional exonic variants assayed on the Illumina HumanExome BeadChip. We did not observe any individual protein-altering variants that are reproducibly associated with extremely high intelligence and within the entire distribution of intelligence. Moreover, no significant associat...
Because general cognitive ability (g) is among the most heritable behavioural traits, it is a rea... more Because general cognitive ability (g) is among the most heritable behavioural traits, it is a reasonable target for a search for quantitative trait loci (QTLs). We used a selected-extremes design to test candidate genes for allelic association with g. Polymorphisms in four genes in the dopamine system (DRD2, DRD3, DRD4, DAT1) were genotyped for 51 high g children with IQ scores > 130 and for 51 average g control children. No significant allelic or genotypic differences were found between the high g and average g groups for these markers of the dopamine system, even though the selected-extremes design provides power to detect QTL associations that involve a relative risk of about 1.5.
The present study investigated the relationship between forgivingness and action orientation, and... more The present study investigated the relationship between forgivingness and action orientation, and examined the mediating role of action orientation for the neuroticism-forgivingness association. Participants (N = 210) completed the Tendency to Forgive Scale (TTF; Brown, 2003), two subscales from the Action Control Scale (ACS-90; Kuhl, 1994b) and the Neuroticism scale from the short form of the Big Five Inventory (BFI-K; Rammstedt & John, 2005). Results indicate that failure-related action orientation (AOF) was strongly positively related to forgivingness. Moreover, the negative relation between neuroticism and forgivingness was fully mediated by action orientation (AOF). This finding suggests that the ability to down-regulate negative affect is an important mechanism in explaining the association between neuroticism and forgivingness.
Unrelated H alf-Siblings S iblings DZ Twins K in sh ip G ro u p MZ Twins S tability Figure 1.7. C... more Unrelated H alf-Siblings S iblings DZ Twins K in sh ip G ro u p MZ Twins S tability Figure 1.7. C orrelations and sam ple sizes for adult sam ples from five kinship groups reared apart and reared together. that include children (Bouchard & M cGue, 1981) except for the group o f unrelated individuals reared together. I f the intellectual assessment is carried out in childhood, unrelated individuals reared together show modest degrees o f sim ilarity (see fig. 1.8).2 There are som e inconsistencies in these data. These are brought out nicely in figure 1.9, where we show simple heritability estimates for adults, using the data from figure 1.7. The first four estimates, which are based on different groups, are entirely independent o f each other and are direct estimates. Follow ing the logic o f the path diagram, for the reared-apart kin the half-sibling correlation is simply multiplied by four; the sibling and DZ twin correlations are multiplied by two, and the M ZA correlation is taken as a direct estimate o f h2. The estimates o f half siblings reared apart and siblings reared apart are based on small sample sizes and consequently have large standard errors. The high Falconer heritabilities suggest that perhaps nonadditive genetic variance may be im portant for IQ ; this suggestion is confirm ed in the study by Pedersen, Plom in, Nesselroade, and M cClearn (1 9 9 2) discussed below. Plom in and Loehlin (1989) fit models to the large body o f kin IQ data, 2. An additional study of unrelated individuals reared together has appeared since figure 1.8 was prepared. Scarr, Weinberg, & Waldman (1993) report a correlation of .19. The weighted average used in the figure changes very little with the addition of this new datum. Source: M cG ue & Bouchard (1 9 8 9). Note: Sam ple sizes range from 111 to 135. Correlations significant at p < .05 are indicated in boldface type. Segal, & Tellegen, 1990), the average correlation between IQ and parental edu cation is .05. Consistent with a genetic interpretation o f the Tom linson-Keasey and Little data, in large-scale studies o f biological families, the m other's educa tion is seldom correlated m ore highly with the child's IQ than the father's education is. The weighted mean values are .303 for fathers' education and .295 for m others' education (N = 34,714, from four studies; Bouchard & Segal, 1985). This is also true in both the Terman data and the Scarr and W einberg data. We would argue that an environm ental explanation along the lines sug gested by Tom linson-Keasey and Little would require at least a slightly higher correlation between m other and offspring than between father and offspring. Genetic theory does not make this prediction. The same lack o f difference holds for the correlation between parents' IQ and their children's IQ (Bouchard & M cGue, 1981). Again, this outcom e is expected on the basis o f a genetic model, but not on the basis o f an environm ental one. The Tom linson-Keasey and Little results are also incom patible with the very m odest correlations between the IQ scores o f unrelated children reared together, as reported above. T he specifics o f the argum ent are unim portant. This study employs a sample o f individuals reared by their biological parents; consequently, all o f the parent-offspring correlations are ambiguous. An adult sample o f adoptees is m andatory if the Sources: Moloney, Bouchard, & Segal (1 9 9 1). Note: Correlations significant at p < .05 are indicated in boldface type.
How early in development do promising signs for differing forms of eminence emerge? Given the eve... more How early in development do promising signs for differing forms of eminence emerge? Given the ever-increasing emphasis on human capital in our conceptual economy and the importance of staying economically competitive in a "flat world" (Friedman, 2007; Rindermann & Thompson, 2011; Zakaria, 2011), this question has implications beyond a theoretical understanding of how exceptional careers develop (Lubinski & Benbow, 2000; Murray, 2003; Simonton, 2014). Studies of intellectually precocious youth have already revealed that assessing the level and pattern of abilities within the top 1% (which constitutes over one third of the ability range) is critical for understanding contrasting creative accomplishments and high-impact careers (Lubinski, 2016; Makel, Kell, Lubinski, Putallaz, & Benbow, 2016). More ability matters, as does the ability pattern. The former is related to the magnitude of accomplishment, whereas the latter is related to the nature of the fields pursued. In addition, information regarding personal preferences is also essential to accurately model the unfolding of exceptional careers that maintain and advance modern cultures. This investigation examined the extent to which two distinct ability and preference constellations (math/ scientific and verbal/humanistic) assessed at age 13 in intellectually precocious youth predict distinct forms of eminence 35 years later. In past research with intellectually precocious 13-year-olds, Achter, Lubinski, Benbow, and Eftekhari-Sanjani (1999) showed that psychometric assessments of abilities and preferences each add value to the prediction of concrete educational outcomes 10 years later. Subsequently, Wai, Lubinski, and Benbow (2005) successfully used the math/scientific 822524P SSXXX10.
Reported is the 20-year follow-up of 1,975 mathematically gifted adolescents (top 1%) whose asses... more Reported is the 20-year follow-up of 1,975 mathematically gifted adolescents (top 1%) whose assessments at age 12 to 14 revealed robust gender differences in mathematical reasoning ability. Both sexes became exceptional achievers and perceived themselves as such; they reported uniformly high levels of degree attainment and satisfaction with both their career direction and their overall success. The earlier sex differences in mathematical reasoning ability did predict differential educational and occupational outcomes. The observed differences also appeared to be a function of sex differences in preferences for (a) inorganic versus organic disciplines and (b) a career-focused versus more-balanced life. Because profile differences in abilities and preferences are longitudinally stable, males probably will remain more represented in some disciplines, whereas females are likely to remain more represented in others. These data have policy implications for higher education and the world of work.
Although much genetic research has addressed normal variation in intelligence, little is known ab... more Although much genetic research has addressed normal variation in intelligence, little is known about the etiology of high cognitive abilities. Using data from 11,000 twin pairs (age range = 6-71 years) from the Genetics of High Cognitive Abilities (GHCA) Consortium, we investigated the genetic and environmental etiologies of high general cognitive ability (g). Age-appropriate psychometric cognitive tests were administered to the twins and used to create g scores standardized within each study. Liability-threshold model fitting was used to estimate genetic and environmental parameters for the top 15% of the distribution of g. Genetic influence for high g was substantial (0.50, with a 95% confidence interval of 0.41-0.60). Shared environmental influences were moderate (0.28, 0.19-0.37). We conclude that genetic variation contributes substantially to high g in Australia, the Netherlands, the United Kingdom and the United States.
A sample of 1,586 intellectually talented adolescents (top 1%) were assessed on the math portion ... more A sample of 1,586 intellectually talented adolescents (top 1%) were assessed on the math portion of the SAT by age 13 and tracked for more than 25 years. Patents and scientific publications were used as criteria for scientific and technological accomplishment. Participants were categorized according to whether their terminal degree was a bachelor's, master's, or doctorate degree, and within these degree groupings, the proportion of participants with at least one patent or scientific publication in adulthood increased as a function of this early SAT assessment. Information about individual differences in cognitive ability (even when measured in early adolescence) can predict differential creative potential in science and technology within populations that have advanced educational degrees.
There is increasing evidence for the role of rare copy-number variation (CNV) in the development ... more There is increasing evidence for the role of rare copy-number variation (CNV) in the development of neuropsychiatric disorders. It is likely that such variants also have an effect on the variation of cognition in what is considered the ''normal'' phenotypic range. The role of rare CNV ([20 KB in length; frequency \5 %) on general cognitive ability is investigated in a sample of 800 individuals (mean age = 16.5, SD = 1.2) using copy-number variants called from the Illumina 610K SNP genotyping array with the software Quanti-SNP. We assessed three measures of CNV burden-total CNV length, number of CNV and average CNV length-for both deletions and duplications in combination and separately. No correlation was found between any of the measures of CNV burden and IQ, or when comparing the top and bottom 10 % of the sample for IQ, both on a genome-wide scale and at individual positions across the genome.
Students identified by talent search programs were studied to determine whether spatial ability c... more Students identified by talent search programs were studied to determine whether spatial ability could uncover math-science promise. In Phase 1, interests and values of intellectually talented adolescents (617 boys, 443 girls) were compared with those of top math-science graduate students (368 men, 346 women) as a function of their standing on spatial visualization to assess their potential fit with math-science careers. In Phase 2, 5-year longitudinal analyses revealed that spatial ability coalesces with a constellation of personal preferences indicative of fit for pursuing scientific careers and adds incremental validity beyond preferences in predicting mathscience criteria. In Phase 3, data from participants with Scholastic Aptitude Test (SAT) scores were analyzed longitudinally, and a salient math-science constellation again emerged (with which spatial ability and SAT-Math were consistently positively correlated and SAT-Verbal was negatively correlated). Results across the 3 phases triangulate to suggest that adding spatial ability to talent search identification procedures (currently restricted to mathematical and verbal ability) could uncover a neglected pool of math-science talent and holds promise for refining our understanding of intellectually talented youth.
This longitudinal study tracked 1,110 adolescents identified as mathematically precocious at Age ... more This longitudinal study tracked 1,110 adolescents identified as mathematically precocious at Age 13 (top 1%) with plans for a math-science undergraduate major. Participants' high school educational experiences, abilities, and interests predicted whether their attained undergraduate degrees were within math-science or nonmath-nonscience areas. More women than men eventually completed undergraduate degrees outside math-science, but many individuals who completed nonmath-nonscience degrees ultimately chose math-science occupations (and vice versa). At Age 33, the 2 degree groups reported commensurate and uniformly high levels of career satisfaction, success, and life satisfaction. Assessing individual differences is critical for modeling talent development and life satisfaction; it reveals that equal male-female representation across disciplines may not be as simple to accomplish as many policy discussions imply. The male-female disparity in math and science is well documented and is particularly apparent at rising levels along the educational-vocational continuum ( Lane
Talent-search participants (286 males, 94 females) scoring in the top 0.01% on cognitive-ability ... more Talent-search participants (286 males, 94 females) scoring in the top 0.01% on cognitive-ability measures were identified before age 13 and tracked over 20 years. Their creative, occupational, and life accomplishments are compared with those of graduate students (299 males, 287 females) enrolled in top-ranked U.S. mathematics, engineering, and physical science programs in 1992 and tracked over 10 years. By their mid-30s, the two groups achieved comparable and exceptional success (e.g., securing top tenure-track positions) and reported high and commensurate career and life satisfaction. College entrance exams administered to intellectually precocious youth uncover extraordinary potential for careers requiring creativity and scientific and technological innovation in the information age.
Journal of Personality and Social Psychology, 2009
Work preferences, life values, and personal views of top math/science graduate students (275 men,... more Work preferences, life values, and personal views of top math/science graduate students (275 men, 255 women) were assessed at ages 25 and 35 years. In Study 1, analyses of work preferences revealed developmental changes and gender differences in priorities: Some gender differences increased over time and increased more among parents than among childless participants, seemingly because the mothers' priorities changed. In Study 2, gender differences in the graduate students' life values and personal views at age 35 were compared with those of profoundly gifted participants (top 1 in 10,000, identified by age 13 and tracked for 20 years: 265 men, 84 women). Again, gender differences were larger among parents. Across both cohorts, men appeared to assume a more agentic, career-focused perspective than women did, placing more importance on creating high-impact products, receiving compensation, taking risks, and gaining recognition as the best in their fields. Women appeared to favor a more communal, holistic perspective, emphasizing community, family, friendships, and less time devoted to career. Gender differences in life priorities, which intensify during parenthood, anticipated differential male-female representation in high-level and timeintensive careers, even among talented men and women with similar profiles of abilities, vocational interests, and educational experiences.
We used a case-control genome-wide association (GWA) design with cases consisting of 1238 individ... more We used a case-control genome-wide association (GWA) design with cases consisting of 1238 individuals from the top 0.0003 (~170 mean IQ) of the population distribution of intelligence and 8172 unselected population-based controls. The single-nucleotide polymorphism heritability for the extreme IQ trait was 0.33 (0.02), which is the highest so far for a cognitive phenotype, and significant genome-wide genetic correlations of 0.78 were observed with educational attainment and 0.86 with population IQ. Three variants in locus ADAM12 achieved genome-wide significance, although they did not replicate with published GWA analyses of normal-range IQ or educational attainment. A genome-wide polygenic score constructed from the GWA results accounted for 1.6% of the variance of intelligence in the normal range in an unselected sample of 3414 individuals, which is comparable to the variance explained by GWA studies of intelligence with substantially larger sample sizes. The gene family plexins, members of which are mutated in several monogenic neurodevelopmental disorders, was significantly enriched for associations with high IQ. This study shows the utility of extreme trait selection for genetic study of intelligence and suggests that extremely high intelligence is continuous genetically with normal-range intelligence in the population.
Although individual differences in intelligence (general cognitive ability) are highly heritable,... more Although individual differences in intelligence (general cognitive ability) are highly heritable, molecular genetic analyses to date have had limited success in identifying specific loci responsible for its heritability. This study is the first to investigate exome variation in individuals of extremely high intelligence. Under the quantitative genetic model, sampling from the high extreme of the distribution should provide increased power to detect associations. We therefore performed a case–control association analysis with 1409 individuals drawn from the top 0.0003 (IQ >170) of the population distribution of intelligence and 3253 unselected population-based controls. Our analysis focused on putative functional exonic variants assayed on the Illumina HumanExome BeadChip. We did not observe any individual protein-altering variants that are reproducibly associated with extremely high intelligence and within the entire distribution of intelligence. Moreover, no significant associat...
Because general cognitive ability (g) is among the most heritable behavioural traits, it is a rea... more Because general cognitive ability (g) is among the most heritable behavioural traits, it is a reasonable target for a search for quantitative trait loci (QTLs). We used a selected-extremes design to test candidate genes for allelic association with g. Polymorphisms in four genes in the dopamine system (DRD2, DRD3, DRD4, DAT1) were genotyped for 51 high g children with IQ scores &amp;amp;gt; 130 and for 51 average g control children. No significant allelic or genotypic differences were found between the high g and average g groups for these markers of the dopamine system, even though the selected-extremes design provides power to detect QTL associations that involve a relative risk of about 1.5.
The present study investigated the relationship between forgivingness and action orientation, and... more The present study investigated the relationship between forgivingness and action orientation, and examined the mediating role of action orientation for the neuroticism-forgivingness association. Participants (N = 210) completed the Tendency to Forgive Scale (TTF; Brown, 2003), two subscales from the Action Control Scale (ACS-90; Kuhl, 1994b) and the Neuroticism scale from the short form of the Big Five Inventory (BFI-K; Rammstedt & John, 2005). Results indicate that failure-related action orientation (AOF) was strongly positively related to forgivingness. Moreover, the negative relation between neuroticism and forgivingness was fully mediated by action orientation (AOF). This finding suggests that the ability to down-regulate negative affect is an important mechanism in explaining the association between neuroticism and forgivingness.
Unrelated H alf-Siblings S iblings DZ Twins K in sh ip G ro u p MZ Twins S tability Figure 1.7. C... more Unrelated H alf-Siblings S iblings DZ Twins K in sh ip G ro u p MZ Twins S tability Figure 1.7. C orrelations and sam ple sizes for adult sam ples from five kinship groups reared apart and reared together. that include children (Bouchard & M cGue, 1981) except for the group o f unrelated individuals reared together. I f the intellectual assessment is carried out in childhood, unrelated individuals reared together show modest degrees o f sim ilarity (see fig. 1.8).2 There are som e inconsistencies in these data. These are brought out nicely in figure 1.9, where we show simple heritability estimates for adults, using the data from figure 1.7. The first four estimates, which are based on different groups, are entirely independent o f each other and are direct estimates. Follow ing the logic o f the path diagram, for the reared-apart kin the half-sibling correlation is simply multiplied by four; the sibling and DZ twin correlations are multiplied by two, and the M ZA correlation is taken as a direct estimate o f h2. The estimates o f half siblings reared apart and siblings reared apart are based on small sample sizes and consequently have large standard errors. The high Falconer heritabilities suggest that perhaps nonadditive genetic variance may be im portant for IQ ; this suggestion is confirm ed in the study by Pedersen, Plom in, Nesselroade, and M cClearn (1 9 9 2) discussed below. Plom in and Loehlin (1989) fit models to the large body o f kin IQ data, 2. An additional study of unrelated individuals reared together has appeared since figure 1.8 was prepared. Scarr, Weinberg, & Waldman (1993) report a correlation of .19. The weighted average used in the figure changes very little with the addition of this new datum. Source: M cG ue & Bouchard (1 9 8 9). Note: Sam ple sizes range from 111 to 135. Correlations significant at p < .05 are indicated in boldface type. Segal, & Tellegen, 1990), the average correlation between IQ and parental edu cation is .05. Consistent with a genetic interpretation o f the Tom linson-Keasey and Little data, in large-scale studies o f biological families, the m other's educa tion is seldom correlated m ore highly with the child's IQ than the father's education is. The weighted mean values are .303 for fathers' education and .295 for m others' education (N = 34,714, from four studies; Bouchard & Segal, 1985). This is also true in both the Terman data and the Scarr and W einberg data. We would argue that an environm ental explanation along the lines sug gested by Tom linson-Keasey and Little would require at least a slightly higher correlation between m other and offspring than between father and offspring. Genetic theory does not make this prediction. The same lack o f difference holds for the correlation between parents' IQ and their children's IQ (Bouchard & M cGue, 1981). Again, this outcom e is expected on the basis o f a genetic model, but not on the basis o f an environm ental one. The Tom linson-Keasey and Little results are also incom patible with the very m odest correlations between the IQ scores o f unrelated children reared together, as reported above. T he specifics o f the argum ent are unim portant. This study employs a sample o f individuals reared by their biological parents; consequently, all o f the parent-offspring correlations are ambiguous. An adult sample o f adoptees is m andatory if the Sources: Moloney, Bouchard, & Segal (1 9 9 1). Note: Correlations significant at p < .05 are indicated in boldface type.
Uploads
Papers by David Lubinski