All else being equal: Are men always higher in social dominance orientation than women?

The belief in the gender invariance of many traits is a view that dominates much of psychology. In social psychology, this position is clearly represented by social dominance theory and the construct of social dominance orientation (SDO) where it is argued that, all else being equal, men will be higher in SDO than women. In other domains, though, these assumptions are being questioned, and researchers are arguing for a gender similarities hypothesis. The argument is that men and women are more similar than different, and where there are effects for gender, these are small. In this investigation, men and women are compared under similar cultural (Study 1), ideological, (Study 2) and status (Study 3) contexts to examine whether, all else being equal, men really are higher in SDO than women. In an additional study (Study 4), a meta‐analysis is conducted aggregating the effect sizes of the previous studies. Results demonstrated either no effect for gender or an interaction between gender and the relevant social context and only a small effect size of gender—findings that disconfirm the ceteris paribus assumption of social dominance theory. In conclusion, the implications of the findings for understanding gender effects in social psychology are discussed. Copyright © 2011 John Wiley & Sons, Ltd.     

Improving general intelligence with a nutrient-based pharmacological intervention

Cognitive enhancing substances such as amphetamine and modafinil have become popular in recent years to improve acute cognitive performance particularly in environments in which enhanced cognition or intelligence is required. Nutraceutical nootropics, which are natural substances that have the ability to bring about acute or chronic changes in cognition have also been gaining popularity in a range of settings and applications including the workplace, driving and in the amelioration of age related cognitive decline. Huperzine A, Vinpocetine, Acetyl-l-carnitine, Rhodiola Rosea and Alpha-lipoic Acid are popular nutritional supplements that have shown promising benefits in improving a range of biological (e.g., blood flow, anti-inflammatory, anti-oxidant, and direct neurotransmitter effects) and cognitive processes from in vitro, animal and human clinical research. We report here the first human randomized clinical trial for cognition in which we administer a combination of Huperzine A, Vinpocetine, Acetyl-l-carnitine, R. Rosea and Alpha-lipoic acid (called Ceretrophin) vs placebo. Sixty participants (40 females and 20 males, with a mean age of 45.4 years, SD = 12.6) completed either the odd or even items from the Raven Advanced Progressive Matrices (APM) at baseline and the opposite odd or even items at week 4 after consuming either the combination nootropic or placebo. A significant study visit (time) × treatment condition interaction was found: F (1, 57) = 7.279, p = 0.009, partial η² = .113, with paired samples t-tests revealing a significant improvement in mean APM score from baseline to retest (week 4) (t(34) = ? 4.045, p < .001) for the Ceretrophin? group. Improvements in APM scores could be attributed to the active intervention over the placebo, indicating that the treatment improved general intelligence. Implications for improving our understanding of the biological basis of intelligence and pharmacologically improving human cognition are discussed.     

Both odor identification and ApoE-ε4 contribute to normative cognitive aging

Research indicates that apoliprotein E (ApoE) plays a role in the development of Alzheimer's disease (AD) and possibly in the cognitive decline associated with normative aging. More recently, researchers have shown that ApoE is expressed in olfactory brain structures, and a relationship among ApoE, AD, and olfactory function has been proposed. In the current analyses, we investigated the contribution of ApoE and odor identification in decline trajectories associated with normative cognitive aging in various domains, using longitudinal data on cognitive performance available from the Swedish Adoption/Twin Study of Aging. Data on both ApoE status and olfactory functioning were available from 455 individuals ranging in age from 50 to 88 years at the first measurement occasion. Odor identification was measured via a mailed survey. Cognitive performance was assessed in up to 5 waves of in-person testing covering a period of 16 years. Latent growth curve analyses incorporating odor identification and ApoE status indicated a main effect of odor identification on the performance level in three cognitive domains: verbal, memory, and speed. A main effect of ApoE on rates of decline after age 65 was found for verbal, spatial, and speed factors. The consistency of results across cognitive domains provides support for theories that posit central nervous system-wide origins of the olfaction-cognition-ApoE relationship; however, olfactory errors and APOE ε4 show unique and differential effects on cognitive trajectory features.     

Regression analyses of bias on the Kaufman Assessment Battery for Children

The Kaufman Assessment Battery for Children (K-ABC) has been touted in the popular press and the publisher's advertising as a nonbiased measure of children's intellectual functioning. The claims are based substantially on a reduction of the mean differences in overall test performance between blacks and whites on the K-ABC. However, mean differences are the most often rejected indicators of test bias by most serious psychometricians, and while the issue of bias is complex and requires multiple approaches, one necessary test of bias requires a comparison of the predictive validity of the scale for blacks and for whites. The present study reports on the results of an investigation of the criterion-related validity of the K-ABC, predicting reading comprehension, arithmetic, and general achievement, for large samples of blacks and whites tested during the standardization of the battery. The statistical technique of Potthoff is used to test for bias under the regression definition of Cleary. The results are reported separately for several age groups. The Sequential and Mental Processing Composite scales tended to overpredict black children's academic levels, especially on the K-ABC achievement scales. Some differences also occurred with the Simultaneous Processing scale but with less frequency.     

Attention and generalization during a conditional discrimination

A conditional discrimination was established and analyzed, using four pigeons. The discrimination was among four compound stimuli projected on the response key—a white circle or triangle on a red or green background—during two conditions of illumination in the chamber, no illumination or flashing illumination. The two lighting conditions indicated whether the stimuli on the key containing triangles or those containing red would be the occasion for reinforcement. After the discrimination formed, generalization to intermediate and extreme values of the conditional stimulus and the attention of the birds to separate aspects of the stimulus on the key under each of the conditional stimuli were studied. All subjects generalized across values of the conditional stimulus, the lighting of the chamber. But subjects differed in the manner in which they treated the compound stimuli: two tended to attend to one or the other aspect of the stimulus on the key depending on the conditional stimulus, and two offered no evidence of such selective attention. Thus, the differential control of responding by the conditional stimuli cannot be attributed to a shift in attention between the figure and ground aspects of the compound stimuli.     

The change from visible to invisible:

It is argued that the problem of the phenomenal persistence of objects in experience, often called “object permanence,” is actually a problem of the discriminating of persisting from nonpersisting things. A distinction is made between objects that go out of sight and objects that go out of existence, and it is shown that optical information exists to distinguish these two cases. Evidence is provided from a series of motion picture displays to suggest that Os do in fact distinguish them. The various optical transitions are shown to be reversing in the first case, but nonreversing in the second. In particular, the transition that specifies the occlusion of one surface by another is analyzed, together with the inverse of this transition. This study is a sequel to an earlier one of optical transformations.     

A developmental study of schedule-induced polydipsia in the rat

Rats 30, 60, 90, and 120 days of age were fed 105 45-mg food pellets on a noncontingent VT 70-sec schedule during 14 daily 2-hr sessions. Every animal became polydipsic on this schedule when compared with a schedule in which 105 pellets were presented at the beginning of the session. Mean polydipsic ratios (schedule intake/control intake) ranged from 2.9–5.4. Water intakes (milliliters per 100g body weight) did not differ during the last five sessions as a function of age. The results are discussed with respect to the generality of the class of adjunctive behaviors.     

Recognition memory for elements of sentences

Although several theoretical positions and a variety of empirical tasks indicate the importance of verbs to sentences, nouns are generally recalled and recognized better in memorial tasks. Three main models can be identified to explain this discrepancy ("Fillenbaum's paradox"). To try to resolve this paradox, several experiments explored the efficiency of various sentence elements as cues in recognition memory. In Experiment I, concreteness of the stimuli did not interact with the type of distractor; however, verb phrase changes were harder to recognize than noun phrase changes when synonym distractors were used. This result was replicated in a forced-choice recognition paradigm (Experiment II) and with whole sentences where the derivational similarity of verbs and nouns was controlled (Experiment IV). The effect could not be attributed to characteristics of the English language (Experiment III) or to superior memory for form information in nouns (Experiment V). The total results are interpreted as suggesting that subjects process different parts of a sentence to different semantic levels, with verbs receiving more semantic representation and nouns more orthographic or phonological representation. The results are taken as support for a "semantic encoding model" of Fillenbaum's paradox.     

Temporal inhibition: effects of changes in rate of reinforcement and rate of responding

Pigeons were trained to key peck on several multiple schedules in which the first of two components was always a simple fixed-interval schedule. The rate of responding at the beginning of the constant fixed-interval schedule was found to decrease with increases in the rate of reinforcement associated with the other component of the multiple schedule, but remained unchanged with decreases in the rate of responding associated with the other component. These results were interpreted as being consistent with the view that the presence and magnitude of the temporal inhibitory effects observed in a given fixed-interval schedule are a function of the properties of reinforcing stimuli, rather than of changes in the rate of responding associated with the time interval immediately preceding the fixed interval in question.     

Discrimination and emission of temporal intervals by pigeons

Because the frequency distribution of IRTs showed little or no control by a DRL schedule, the schedule was modified so that the pigeon's behavior after each IRT would indicate whether or not it had discriminated the duration of the IRT. After every two pecks on a red key, the key changed to blue for 30 sec. Then it automatically became red again. Pecks on the blue key were reinforced with food on a VI schedule only when the preceding IRT on the red key had been longer than 18 sec. The birds did not selectively emit longer IRTs on the red key: the value of IRTs/op did not increase with IRT duration. However, they did discriminate the duration of the IRT emitted on the red key: the rate of pecking on the blue key was an increasing function of the duration of the preceding IRT on the red key.