Measuring Implicit British Perceptions of German Intentions in 1938–1939

Implicit British perceptions of German leaders during the period September 30, 1938–September 1, 1939 (from the Munich Agreements to the German invasion of Poland) are studied with a "ratio of threat accentuation" measure. This ratio is calculated by comparing the densities of power motive imagery in two kinds of archival material: full texts of major Hitler speeches versus summaries in The Times of London, and British versus German accounts of meetings between British diplomats and major Nazi leaders. In both cases, the British ratio of threat accentuation increases following the unexpected German occupation of Prague and the rest of Czechoslovakia on March 15, 1939. These changes in implicit perception are congruent with changes in British explicit perceptions and foreign policy after the German action.     

Preferences for Life-Prolonging Medical Treatments and Deference to the Will of God

We defined and measured a dimension of religiosity frequently invoked in end-of-life (EOL) research—deference to God’s Will (GW)—and examined its relationship to preferences for life-prolonging treatments. In a 35-min telephone interview, 304 older men and women (60 +) were administered the 5-item GW scale, sociodemographic questions, three attitude items regarding length of life, and measures of two health indices, depression, and life-prolonging treatment preferences. The GW scale demonstrated internal consistency (Cronbach’s alpha = .94) and predictive and discriminant validity. Higher scores indicative of greater deference to GW were associated with stronger life-prolonging treatment preferences in poor-prognosis scenarios. Implications for the role of religiosity in medical decision-making are discussed.     

Genes Determine Stability and the Environment Determines Change in Cognitive Ability During 35 Years of Adulthood

ABSTRACT— Previous research has demonstrated stability of cognitive ability and marked heritability during adulthood, but questions remain about the extent to which genetic factors account for this stability. We conducted a 35-year longitudinal assessment of general cognitive ability using the Armed Forces Qualification Test administered to 7,232 male twins in early adulthood and readministered to a subset of 1,237 twins during late middle age. The proportion of variance in cognitive functioning explained by genetic factors was .49 in young adulthood and .57 in late middle age. The correlation between the two administrations was .74 with a genetic correlation of 1.0, indicating that the same genetic influences operated at both times. Genetic factors were primarily responsible for stability, and nonshared environmental factors were primarily responsible for change. The genetic factors influencing cognition may change across other eras, but the same genetic influences are operating from early adulthood to late middle age.     

High impact running improves learning

Regular physical exercise improves cognitive functions and lowers the risk for age-related cognitive decline. Since little is known about the nature and the timing of the underlying mechanisms, we probed whether exercise also has immediate beneficial effects on cognition. Learning performance was assessed directly after high impact anaerobic sprints, low impact aerobic running, or a period of rest in 27 healthy subjects in a randomized cross-over design. Dependent variables comprised learning speed as well as immediate (1 week) and long-term (>8 months) overall success in acquiring a novel vocabulary. Peripheral levels of brain-derived neurotrophic factor (BDNF) and catecholamines (dopamine, epinephrine, norepinephrine) were assessed prior to and after the interventions as well as after learning. We found that vocabulary learning was 20 percent faster after intense physical exercise as compared to the other two conditions. This condition also elicited the strongest increases in BDNF and catecholamine levels. More sustained BDNF levels during learning after intense exercise were related to better short-term learning success, whereas absolute dopamine and epinephrine levels were related to better intermediate (dopamine) and long-term (epinephrine) retentions of the novel vocabulary. Thus, BDNF and two of the catecholamines seem to be mediators by which physical exercise improves learning.     

Adolescent Friendship as a Dynamic System: Entropy and Deviance in the Etiology and Course of Male Antisocial Behavior

A dynamic systems framework was applied to understand the influence of friendship on antisocial behavior from childhood (age 9-10) through adulthood (age 24-25) for Oregon Youth Study males (N = 206). Boys were videotaped interacting with a friend at ages 14, 16, and 18, and deviant content and interpersonal processes were independently coded. Conditional dyadic interpersonal processes were studied as a communication system and summarized by an index of information entropy (F. Attneave, 1959). High entropy scores represent disorganized, unpredictable patterns of interaction, whereas low entropy scores reflect an organized dialogue. Conversations of early-onset antisocial boys and their best friends were less organized and included more deviant content than those of well-adjusted controls. Prediction analyses, however, revealed an interaction between entropy and deviant talk. Consistent with expectation, males with well-organized interactions (i.e., low entropy) but elevated levels of deviant content were most likely to continue antisocial behavior into adulthood. Findings suggest that individual risk for maladaptation may be amplified by early adolescent friendship dynamics organized around deviance.     

Seeing versus doing: two modes of accessing causal knowledge

The ability to derive predictions for the outcomes of potential actions from observational data is one of the hallmarks of true causal reasoning. We present four learning experiments with deterministic and probabilistic data showing that people indeed make different predictions from causal models, whose parameters were learned in a purely observational learning phase, depending on whether learners believe that an event within the model has been merely observed ("seeing") or was actively manipulated ("doing"). The predictions reflect sensitivity both to the structure of the causal models and to the size of their parameters. This competency is remarkable because the predictions for potential interventions were very different from the patterns that had actually been observed. Whereas associative and probabilistic theories fail, recent developments of causal Bayes net theories provide tools for modeling this competency.     

Femininity and fertility in sisters with twin brothers: prenatal androgenization? Cross-sex socialization?

Are sisters of twin brothers behaviorally or physiologically masculinized? Prenatal exposure to their brothers' androgens and postnatal socialization experiences unique to girls growing up with twin brothers might influence their attitudes, pubertal development, and reproductive histories. To investigate, we studied age- and cohort-matched samples of Finnish sisters from same-sex and opposite-sex twin pairs. Using data from two ongoing longitudinal studies of consecutive birth cohorts of Finnish twins, we assessed pubertal development at ages 11 and 14 and endorsement of attitudes associated with femininity at age 16. We also studied fertility in Finnish women from same- and opposite-sex twin pairs born from 1958 through 1971, obtaining information on their child-bearing histories when they were ages 15 to 28. Results of each comparison were unambiguously negative: There was no evidence of differences between sisters from same- and opposite-sex twin pairs, and thus, no evidence of either androgenization or cross-sex socialization.