Differentiation of intelligence refers to changes in the structure of intelligence that depend on individuals' level of general cognitive ability (ability differentiation hypothesis) or age (developmental differentiation hypothesis). The present article aimed to investigate ability differentiation, developmental differentiation, and their…

Over half of the children in the U.S. experience adversity early in childhood. These experiences, along with conditions in their families and neighborhoods, have profound developmental effects. The bioecological model of development includes these proximal contexts in a theory of development that incorporates the threats and supports present in…

Existing research suggests that repeated bullying victimization is associated with lower levels of educational attainment. However, it is difficult to ascertain whether a true causal association exists since previously reported associations may be confounded by genetic and shared environmental factors that affect both repeated bullying…

The present study examined whether IQ relates systematically to denomination and income within the framework of the "g" nexus, using representative data from the National Longitudinal Study of Youth (NLSY97). Atheists score 1.95 IQ points higher than Agnostics, 3.82 points higher than Liberal persuasions, and 5.89 IQ points higher than…

The United States has the highest incarceration rate in the world, yet there is relatively little information on how the removal of these adults from households impacts the youth who are left behind. This study used a child-centered lens to examine the impact of incarceration on the school outcomes of youth who resided with a family member or…

Although a negative relationship between fertility and education has been described consistently in most countries of the world, less is known about the relationship between intelligence and reproductive outcomes. Also the paths through which intelligence influences reproductive outcomes are uncertain. The present study uses the NLSY79 to analyze…

Although the Flynn Effect has been studied widely across cultural, geographic, and intellectual domains, and many explanatory theories have been proposed, little past research attention has been paid to subgroup differences. Rodgers and Wanstrom (2007) identified an aggregate-level Flynn Effect (FE) at each age between 5 and 13 in the Children of…

Views IQ test scores as measures of general intelligence that relate to the acquisition of knowledge in diverse settings. Discusses studies that support the assertion that IQ has an influence on a socially relevant outcome variable that is independent of its relationship to social status. (MMU)

There is scientific and popular dispute about whether there are sex differences in cognitive abilities and whether they are relevant to the proportions of men and women who attain high-level achievements, such as Nobel Prizes. A recent meta-analysis (Lynn, R., and Irwing, P. (2004). Sex differences on the progressive matrices: a meta-analysis.…

The importance of intelligence quotient (IQ) to income is analyzed using data from the National Longitudinal Survey of Youth, a study that began in 1979 with 12,686 subjects. Data for this study go through the 1994 interview wave, so that the most recent income data is for 1993. Statistical techniques are used to separate the influence of IQ from…

The strongest recent statement that inequality in America is the natural result of a free market came in "The Bell Curve: Intelligence and Class Structure in American Life" by Richard Herrnstein and Charles Murray. These authors argued that intelligence determines how well people do in life, and the rich are rich largely because they are…

Genetic and environmental influences on academic achievement were studied for 314 pairs of white full siblings and 53 pairs of half siblings and 161 pairs of black full siblings and 106 half-sibling pairs (National Longitudinal Survey of Youth). Results support a common heritage view of the growth of academic knowledge. (SLD)

Commentary discusses two components of "The Bell Curve: Intelligence and Class Structure in American Life." First, evidence is presented demonstrating central role intelligence plays in American life; second is Spearman's g, the general factor underlying individual differences involving cognitive ability. Concludes that data does not…

Analysis of data on 2,000 children from the National Longitudinal Survey of Youth suggests that maternal intelligence is a significant predictor of scores on the Peabody Picture Vocabulary Test-Revised. The HOME Inventory short forms used in the study are appended. (LB)