Blair's assertion that fluid intelligence (gF) is distinct from general intelligence (g) is contradictory to cumulative evidence from intelligence research, including extant and novel evidence about generational IQ gains (Lynn–Flynn effect). Because of the near unity of gF and g, his hypothetical concept of gF' (gF “purged” of g variance) may well be a phlogiston theory. (Published Online April 5 2006).
Suicidal behavior is an interesting blank space in Keller & Miller's (K&M's) population genetical account on explaining the existence and persistence of common, harmful, heritable mental disorders. I argue that suicidal behavior is yet another of these disorders. It may well be consistent with all three evolutionary models considered by K&M. (Published Online November 9 2006).
Across 85 countries around the world, Voracek (2004) found a significant positive relation between estimated national intelligence (IQ) and national male and female suicide rate. The relation was not attenuated when countriess (1981) evolutionary theory of human suicide, namely that a threshold intelligence is necessary for suicidality and that intelligence and suicide mortality should thus be positively related. Here, further evidence for this hypothesis is bolstered by focusing on suicide rates of the elderly. Across 48 Eurasian countries, estimated national IQ (...) was significantly positively related to national suicide rates of people aged 65 years and over. This new ecological-level finding survived statistical controlling for a set of seven variables (type of national IQ estimation, national GDP, stableness and recency measures for suicide rates, and rates of adult literacy, urbanization and Roman Catholics), which thus are not confounding factors for the relation of intelligence and suicide mortality. Based on ecological data, the threshold IQ for suicidality is predicted to be 70 or slightly over, an estimate that is consistent with various suicidological observations. (shrink)
Simpson and Gangestad's (1991) Sociosexual Orientation Inventory (SOI) is pivotal in Schmitt's cross-national study on sociosexuality. Here I elaborate on psychometric shortcomings of the SOI that are crucial in this research context.
Young men are more distressed by a partner’s sexual infidelity, whereas young women are more distressed by a partner’s emotional infidelity. The present research investigated (a) whether the sex difference in jealousy replicates in an older sample, and (b) whether younger people differ from older people in their selection of the more distressing infidelity scenario. We presented forced-choice dilemmas to 202 older people (mean age = 67 years) and to 234 younger people (mean age = 20 years). The sex difference (...) replicated in the older sample. In addition, older women were less likely than younger women to select a partner’s emotional infidelity as more distressing than a partner’s sexual infidelity. Discussion offers directions for future work on sex differences and age differences in jealousy. (shrink)
According to Roberts, self-experimentation is a viable tool for idea generation in the behavioral sciences. Here we discuss some limitations of this assertion, as well as particular design and data-analytic shortcomings of his experiments.
According to Williams, human facially expressed pain, and its perception by conspecifics, is generated by evolved mechanisms. We argue that a key variable – sex (male, female) – needs to be considered for a complete theory of pain expression and perception. To illustrate, we cite findings on sex differences in pain and pain perception, and in crying and crying responsiveness.