Navigating in a challenging semiarid environment: the use of a route-based mental map by a small-bodied neotropical primate

To increase efficiency in the search for resources, many animals rely on their spatial abilities. Specifically, primates have been reported to use mostly topological and rarely Euclidean maps when navigating in large-scale space. Here, we aimed to investigate if the navigation of wild common marmosets inhabiting a semiarid environment is consistent with a topological representation and how environmental factors affect navigation. We collected 497 h of direct behavioral and GPS information on a group of marmosets using a 2-min instantaneous focal animal sampling technique. We found that our study group reused not only long-route segments (mean of 1007 m) but entire daily routes, a pattern that is not commonly seen in primates. The most frequently reused route segments were the ones closer to feeding sites, distant to resting sites, and in areas sparse in tree vegetation. We also identified a total of 56 clustered direction change points indicating that the group modified their direction of travel. These changes in direction were influenced by their close proximity to resting and feeding sites. Despite our small sample size, the obtained results are important and consistent with the contention that common marmosets navigate using a topological map that seems to benefit these animals in response to the exploitation of clustered exudate trees. Based on our findings, we hypothesize that the Caatinga landscape imposes physical restrictions in our group’s navigation such as gaps in vegetation, small trees and xerophytic plants. This study, based on preliminary evidence, raises the question of whether navigation patterns are an intrinsic characteristic of a species or are ecologically dependent and change according to the environment.

     

Cognitive Load While Learning to Use a Computer Program

There is a growing body of evidence suggesting that many traditional instructional techniques may unnecessarily overload limited working memory and impede learning. Based on cognitive load theory, it was hypothesised that instructional design only takes on a crucial role when there is a high level of interaction between learning elements resulting in those elements having to be simultaneously held in working memory. When there is little, if any, interaction between individual learning elements, then the format of presentation should be inconsequential. These hypotheses were tested using a computer-aided design/computer-aided manufacture (CAD/CAM) package with trainees from a Sydney company. Results showed that when instructions involved high element interactivity, a self-contained manual that physically integrated disparate information and did not require the use of the computer hardware was vastly superior to instructional formats that involved continual interaction with the computer. No differences were found between instructional formats when the learning material entailed low element interactivity. Evidence that these findings were due to cognitive load rather than other factors came from secondary task analysis. In light of these and previous results, suggestions are made for cognitively guided instructional packages.     

Mothers' Perceptions of Infants Labelled ‘Depressed’

Forty-four depressed and non-depressed mothers participated in a videotaped interaction with their own infant and then rated the videotape using the Infant Stereotyping Scale and the Interaction Rating Scale. In addition, one half of the mothers rated a videotape of an unfamiliar infant who was labelled psychologically ‘depressed’ and the other half rated a videotape of the same infant with no label given. Both the depressed and non-depressed mothers rated the ‘depressed’ labelled infant more negatively than the non-labelled infant on the attributes of physical potency, cognitive competence, sociability and difficult behaviour. Physical appearance was the only rating that was not biased by the ‘depressed’ label. Mothers' ratings of their own infants were more positive than their ratings of the non-labelled stimulus infant. Depressed mothers did not see their infants more negatively except on one rating. They rated the physical appearance of their own infant more negatively than non-depressed mothers.     

Sexual jealousy in young women and men: Aggressive responsiveness to partner and rival

Two studies compared judgments about aggressive components of jealous reactions to the partner and to the rival, specifically, emotional (anger), cognitive (blame), and behavioral components. The first study randomly assigned 172 young women and men to two questionnaires on jealous reactions to mild (flirting) and serious (cheating) transgressions. One questionnaire assessed standards for appropriate behavior and perceptions of how people usually react. The second questionnaire asked people to report how they had reacted or, if not experienced with a sexual transgression, how they would react. The second study asked 113 people to imagine a situation in which they knew their partner had been sexually unfaithful. There were three major findings that were interpreted in the context of courtship, a time when attention is focused on the qualities of one's potential long-term partner. First, the jealous individual's anger and blame were focused more on the partner than the rival. Second, mean anger and blame scores given the partner were well matched. In contrast, the rival received more anger and blame than deemed appropriate and considerably more anger than blame. These data suggest that, in the context of courtship, a rival is not simply a competitor. Third, men were more inclined to think about aggressive action against the rival but women were more emotionally and behaviorally reactive to the rival. The latter result implies that, in the context of competition for an established romantic partner, a rival is more salient for women than for men. © 1993 Wiley-Liss, Inc.     

Variation in aggressive behavior and anatomo-physiological correlates generated by crowding without physical contact in the house mouse

Behavioral, physiological (i.e., endocrine), and anatomical consequences of crowding in mice were studied in a situation where animals were in auditory, visual, olfactory, and tactile contact but restrained from full physical interactions, to prevent overt aggression. Males that cohabited with females undisturbed by neighboring conspecifics showed greater propensity to attack same-sex intruders and had higher plasma testosterone levels than did their “crowded” counterparts, that is, males cohabiting with females and housed adjacent to other male/female pairs. In this respect, the latter animals resembled submissive males. However, a significant increase in weight of androgen-dependent target organs (i.e., seminal vesicles and preputial glands) was found in crowded males. These data indicate that despite the observed inhibition of social aggression these males are not physiologically comparable (homologous) to male mice that experienced defeat and the stress of submission during fighting. The intriguing possibility that different conversion pathway of testosterone are accelerated, as a result of social communication, in males living in these two environments and the behavioral implications of these possibilities are discussed. Finally, the parental behavior of crowded animals, although not freely interacting with each other, was disrupted, causing a marked decrease in reproductive success. In this situation a high incidence of infanticide of their offspring by both parents was observed, whereas this behavior was virtually absent in non-crowded male/female pairs.     

Misunderstandings and omissions in textbook accounts of effect sizes

There have been frequent attempts in psychology to reduce the reliance on null hypothesis significance testing (NHST) as the criterion for establishing the importance of results. Many authorities now recommend the reporting of effect sizes (ESs) as a supplement or alternative to NHST. However, there is extensive specialist literature highlighting problems associated with the use and interpretation of ESs. A review of the coverage of ESs in over 100 textbooks on statistical analysis in behavioural science revealed widespread neglect of ESs and the relevant critical issues that have widespread coverage in the more specialist literature. For example, many textbooks claim that ESs should be interpreted as a simple measure of the practical real-world importance of a result despite the fact that ESs are profoundly influenced by features of design and analysis strategy. We seek to highlight areas of misunderstanding about ESs found in the pedagogical literature in the light of the more specialist literature and make recommendations to researchers for the appropriate use and interpretation of ESs. This is critical as statistics textbooks have a crucial role in the education of researchers.     

Parental Involvement and Adolescents’ Academic Achievement: Latent Profiles of Mother and Father Warmth as a Moderating Influence

Parental involvement in their adolescents’ education plays an important role in promoting their children's academic outcomes. Yet, more research is needed to examine the relationship between parenting practices and parental warmth as well as to consider the potential joint contribution of warmth from both fathers and mothers. Thus, the primary purpose of the current study is to examine the extent to which patterns of parental warmth across fathers and mothers moderate the association between parental involvement and adolescents’ grade point average (GPA) and school engagement behaviors. Latent profile analysis was conducted to identify disparate profiles of fathers’ and mothers’ warmth within a nationally representative sample of 2,306 youths (51% male; mean age = 15.31 years, SD = 1.50; 77% non-Hispanic White) residing in opposite-sex, two-parent families from Wave I and II of the National Longitudinal Study of Adolescent to Adult Health. Latent-class enumeration processes support a five-profile solution characterized by differences in levels of parental warmth and congruency across parents: (a) Congruent High Warmth, (b) Congruent Moderate Warmth, (c) Congruent Low Warmth, (d) Incongruent High Mother/Low Father Warmth, and (e) Incongruent Low Father/Lower Mother Warmth. Subsequent multiple linear regression analyses reveal a moderating effect for Congruent Low Warmth on the relationship between parental involvement and adolescents’ GPA. Ultimately, the results show that variation in parental warmth exists across fathers and mothers with differing impact on adolescents’ outcomes. Excluding one parent without considering the joint effects of both parents will not produce an accurate and precise understanding of parenting in research or practice.