The proof of the pudding: an illustration of the relative strengths of null hypothesis, meta-analysis, and Bayesian analysis

Some methodologists have recently suggested that scientific psychology's over-reliance on null hypothesis significance testing (NHST) impedes the progress of the discipline. In response, a number of defenders have maintained that NHST continues to play a vital role in psychological research. Both sides of the argument to date have been presented abstractly. The authors take a different approach to this issue by illustrating the use of NHST along with 2 possible alternatives (meta-analysis as a primary data analysis strategy and Bayesian approaches) in a series of 3 studies. Comparing and contrasting the approaches on actual data brings out the strengths and weaknesses of each approach. The exercise demonstrates that the approaches are not mutually exclusive but instead can be used to complement one another.     

On multiple determinants of racial differences in intelligence: A reply to Jensen

A belief in the multidimensional nature of intelligence prompted Borkowski and Krause (1983) to reexamine the race-IQ controversy from a new theoretical perspective. Jensen has subsequently forced us to look more carefully at data presented in the earlier paper. After we corrected all measures in the perceptual efficiency and executive systems for unreliability and rethought the earlier data, our original conclusions remain tenable: Control processes and metacognitive states are important factors in understanding the sources of race-related differences in intelligence. In accord with the earlier conclusion, we do not deny the association of “speediness” (perceptual efficiency) with race-IQ differences but rather argue for the necessity, and utility, of a broader, multidimensional conceptualization of the nature and growth of intelligence.     

Effects of Gender and Dominance on Leadership Emergence: Incentives Make a Difference

Several decades of laboratory research have shown that high-dominant women, when paired with low-dominant men, are less likely than expected to emerge as leaders on gender-neutral tasks. The current study was designed to investigate the impact of an incentive on leadership emergence in mixed-gender pairs in which one member was high in personality dominance and one was low. Across incentive conditions, men high in personality dominance were more likely than women to emerge as leaders. Under the no-incentive condition, personality dominance relative to men did not significantly improve women’s leadership likelihood; men were more likely to emerge as leaders regardless of personality dominance. However, under the incentive condition, high-dominant women were significantly more likely to emerge as leaders than were their low-dominant male counterparts, and high-dominant men were also more likely than low-dominant women to emerge as leaders.     

Infant information processing and family history of specific language impairment: converging evidence for RAP deficits from two paradigms

An infant's ability to process auditory signals presented in rapid succession (i.e. rapid auditory processing abilities [RAP]) has been shown to predict differences in language outcomes in toddlers and preschool children. Early deficits in RAP abilities may serve as a behavioral marker for language-based learning disabilities. The purpose of this study is to determine if performance on infant information processing measures designed to tap RAP and global processing skills differ as a function of family history of specific language impairment (SLI) and/or the particular demand characteristics of the paradigm used. Seventeen 6- to 9-month-old infants from families with a history of specific language impairment (FH+) and 29 control infants (FH-) participated in this study. Infants' performance on two different RAP paradigms (head-turn procedure [HT] and auditory-visual habituation/recognition memory [AVH/RM]) and on a global processing task (visual habituation/recognition memory [VH/RM]) was assessed at 6 and 9 months. Toddler language and cognitive skills were evaluated at 12 and 16 months. A number of significant group differences were seen: FH+ infants showed significantly poorer discrimination of fast rate stimuli on both RAP tasks, took longer to habituate on both habituation/recognition memory measures, and had lower novelty preference scores on the visual habituation/recognition memory task. Infants' performance on the two RAP measures provided independent but converging contributions to outcome. Thus, different mechanisms appear to underlie performance on operantly conditioned tasks as compared to habituation/recognition memory paradigms. Further, infant RAP processing abilities predicted to 12- and 16-month language scores above and beyond family history of SLI. The results of this study provide additional support for the validity of infant RAP abilities as a behavioral marker for later language outcome. Finally, this is the first study to use a battery of infant tasks to demonstrate multi-modal processing deficits in infants at risk for SLI.