Energetic Cost and Stability during Human Walking at the Preferred Stride Frequency

The possibility that preferred modes of locomotion emerge from dynamical and optimality constraints and the energetic and dynamical constraints on preferred and predicted walking frequency are explored in this article. Participants were required to walk on a treadmill at their preferred frequency, at a frequency predicted as the resonance of a hybrid pendulum-spring model of the legs, and at frequencies ±15%, ±25%, ±35% of the predicted frequency. Walking at the preferred and predicted frequencies resulted in minimal metabolic costs and maximal stability of the head and joint actions. Mechanical energy conservation was constant across conditions. The head was more stable than the joints. The joints appeared to be in service of the head in maintaining a stable trajectory. The major findings of this study suggest a complementary relationship between energetic (physiological) and stability constraints in the adoption of a preferred frequency of walking. Multiple subsystems may be involved in constraining observed macroscopic behavior in intact biological systems. The approach and results of the study imply that a useful tack in understanding how dynamical control structures arise is to study the potential criteria that serve to act as constraints on skilled movement patterns in unimpaired and impaired populations.     

Transferring Subcultural Knowledge On-Line: Practices and Beliefs of Persistent Digital Pirates

Criminal subcultures form around deviant behaviors as a consequence of persistent interactions with like-minded others who facilitate the transmission of norms, values, and belief. Although researchers have explored social interactions in the real world, few have considered how learning occurs through virtual interactions. We address the role of on-line interactions in spreading subcultural knowledge by interviewing 34 persistent digital pirates and performing a non-participant ethnography of an on-line forum devoted to piracy. Our results show that through on-line interactions, pirates learn the norms and values of digital piracy, including how to recognize and avoid risks associated with pirating and how to make sense of and justify their actions. They did not see themselves as members of a piracy subculture, however. These findings show that subcultural knowledge can be transmitted through on-line interactions, even when participants do not fully invest in the group.     

The relationship between religious beliefs and behaviours and changes in Spiritual Health Locus of Control over time in a national sample of African-Americans

Using data from a sample of African-Americans, the present study examined the role of religious beliefs and behaviours in predicting changes in Spiritual Health Locus of Control (SHLOC), or beliefs about the role that God plays in a person’s health. A national sample of African-American adults was recruited using a telephone survey and re-contacted 2.5 years later. Overall, results indicated that both higher religious beliefs and behaviours predicted increases in Active SHLOC, or the view that one collaboratively works with God to maintain one’s health. However, only religious behaviours predicted increases in Passive SHLOC, or the view that because God is in complete control of health that one’s own behaviours are unnecessary. Among men, religious beliefs predicted strengthening Active SHLOC beliefs, while religious behaviours predicted growing Passive SHLOC beliefs. Among women, religious behaviours predicted strengthening Active and Passive SHLOC beliefs.     

Counselors' Models of Helping: Addressing the Needs of the Culturally Different Client in School Settings

This study examined the attributions made by school counselors about responsibility for the causes of and solutions to students' problems. A total of 433 school counselors completed an instrument measuring attributions of responsibility and controllability of student problems. The hypothesis was supported that school counselors' attribution styles differ according to counselor ethnicity. Este estudio examinó las atribuciones hechas por consejeros de escuela acerca de responsabilidad para las causas de y de las soluciones a los problemas de los estudiantes. Un suma de 433 consejeros de la escuela completó un instrumento que mide atribuciones de responsabilidad y la habilidad de controlar los problemas de los estudiantes. La hipótesis se sostuvo que los estilos de atribución de los consejeros de escuela se difieren según el origin étnico del consejero.     

Delay discounting in the pigeon: In search of a magnitude effect

The magnitude effect, where larger outcomes are discounted proportionally less than smaller outcomes, is a well‐established phenomenon in delay discounting by human participants. To this point in the literature magnitude effects have not been reliably evidenced in nonhuman animals. , however, used a concurrent‐chains arrangement with pigeon and found evidence for a magnitude effect. Grace et al. suggested that in many delay discounting experimental arrangements with nonhuman animals (e.g., adjusting amount, adjusting delay) the organism is not given the opportunity to directly compare outcomes of different sizes. They suggest that because of the lack of direct comparison it is difficult for the organism to determine the relative size of each outcome, which in turn mutes the effect of the amount differences between outcomes. As a test of this “comparison hypothesis,” the present experiment was conducted to assess whether the magnitude effect would be evidenced in pigeon when using an adjusting amount procedure where outcomes of different amounts were presented proximally. In the present arrangement, pigeons were presented two choice panels in an operant chamber where each panel was associated with an independent adjusting amount delay discounting task, but with differing outcome amounts (i.e., a 32‐food pellet panel and an 8‐food pellet panel). In this arrangement the choice panels alternated in their availability within a session from trial block to trial block. The present findings indicate no reliable effect of amount, even when the outcomes were proximal and thus readily comparable. This result suggests that the lack of magnitude effect is not driven by the organism's ability to compare the difference in amount between choice alternatives.     

Preference reversals with losses

People who prefer larger, later gains over smaller, sooner gains when considering outcomes far in the future often reverse their preference as the alternatives become closer in time. This finding, which is contrary to a normative economic account of intertemporal choice, has been interpreted as support for hyperboloid discounting, but the results can also be explained by steeper discounting of smaller amounts. The present study is the first to demonstrate that analogous preference reversals occur with losses: People who preferred a smaller, sooner loss over a larger, later loss when the outcomes were far in the future reversed their preference when these alternatives were closer in time. Because there was no magnitude effect (i.e., smaller losses were not discounted more steeply than larger losses), the present findings strongly support the proposition that reversals in preference between delayed outcomes occur because of the hyperboloid shape of the discounting function.     

Parental involvement in competitive youth sport settings

ObjectivesBased on ecological systems theory [Bronfenbrenner, U. (2005). Making human beings human: Bioecological perspectives on human development. Thousand Oaks, CA: Sage], the purpose of this study was to examine parents’ involvement in competitive youth sport settings.DesignData were collected through two distinct phases of fieldwork. Phase 1 involved longitudinal data collection with four families. Phase 2 involved observations of youth soccer settings.MethodData were collected from four families via individual interviews and audio-diaries and were supplemented through 120 h of observation. Data were transcribed verbatim and analyzed using grounded theory methodology.ResultsParents’ verbal reactions to their children's sport performance behaviors were placed on a continuum moving from more supportive to more controlling comments. These comments were categorized as praise/encouragement, performance contingent feedback, instruction, striking a balance, negative comments, and derogatory comments. Parents experienced empathy in that they perceived sharing the emotions their children felt in sport, and these emotions appeared to change in relation to dynamic game and contextual circumstances. Parents also thought that they possessed knowledge and expertise of sport, which they perceived enabled them to make comments to their children.ConclusionA series of reciprocal and bi-directional relationships were central to parents’ involvement in competitive youth sport.     

Influence of Gender Roles on Perceptions of Teacher/Adolescent Student Sexual Relations

In this study we explored the effects of respondent gender and the specific gender combination (i.e., cross- and same-gender dyads) on perceptions of a sexual encounter between a teacher and an adolescent student. Respondents (120 male and 120 female undergraduates) read a brief scenario and answered questions about their perceptions of the encounter. Significant interactions emerged between teacher gender and student gender. For example, the male teacher/male student dyad was viewed as the least normative, and the female teacher/male student dyad was perceived as the most normative. Significant interactions also were found between teacher gender and respondent gender. Results generally were consistent with gender role stereotypes.