The Development of Compensatory Stepping Skills in Children

The development of the ability to use the step for balance recovery was studied among twenty-five 9- to 19-month-old children. The children were grouped according to walking experience (4 levels) and exposed to backward support surface translations, 8 cm in amplitude, under 3 velocity conditions: 15, 20, and 25 cm/s. New walkers (up to 2 weeks' walking experience) used the step infrequently and ineffectively in response to threats to balance. Intermediate walkers (1-3 months' walking experience) showed an increasing use of the step and significant improvement in step execution compared with new walkers. Advanced walkers (> 3 months' walking experience) experienced no falls throughout the protocol, capturing balance with feet-in-place or step responses under all perturbation conditions. A significant developmental transition in the emergence of the compensatory step occurred between the new walker and the intermediate walker experience levels, that is, within the first 3 months of walking experience. Three to 6 months' experience was required for the development of an effective stepping response. A concomitant change in mediolateral stability paralleled the emergence of compensatory stepping.     

Index for Volume 24

In this article, the development of the increasingly differentiated control of the joints necessary to transform the spontaneous leg movements of early infancy into adaptive and functional actions is described. The hypothesis—that increasing joint control requires the capability for disassociation of joint action, the active modulation of joint stiffness, and a transition from proximal to distal control of the joints—is proposed. Kinematic and kinetic analyses of the vertical kicks of infants 2 weeks, 3 months, and 7 months of age (as well as a comparative group of adults) indicated increasing joint independence as well as phase-dependent and joint-dependent control modifications. The kicks of the younger infants were dominated by a proximal control strategy and minimal adjustments of the limb energetics during the flexion and extension phases of the kick. By 7 months of age, much larger modulations of the kick phases were observed as well as increasing evidence of distal control. These results revealed kinematic and kinetic patterns of emerging limb control between 2 weeks and 7 months of age.     

Love Never Ends Well: Termination as the Fate of an Illusion: Commentary on Papers by Jill Salberg and Sue Grand

The following is a discussion of the papers by Jill Salberg and Sue Grand on the topic of psychoanalytic termination. The discussion focuses on the idiosyncratic nature of the psychoanalytic relationship and the particular nature of its ending, some similarities between the end of analytic love and the loss of love in every day life, problems with analyst initiated terminations, and the transgressive nature of termination and analytic creativity. There is a discussion of the cases presented by each of the authors.     

Evidence for Use of Mathematical Inversion By Three-Year-Old Children

The principle of inversion—that a + b ? b must equal a—requires a sensitivity to the relation between addition and subtraction that is critical for understanding arithmetic. Use of inversion, albeit inconsistent, has been observed in school-age children, but when use of a computational shortcut based on inversion emerges and how awareness of the inversion principle relates to other mathematical or numerical skills remain unclear. Two possibilities were explored in 3-year-olds by adapting a method used previously with older children involving the addition and subtraction of blocks differing in length. These children were significantly more accurate on inversion than standard problems, this difference was observed even in children who did not count well, and performance did not differ between formats that afforded qualitative or quantitative solutions. Thus, 3-year-olds appear to develop an early sensitivity to quantitative inversion.     

Against the odds: academic underdogs benefit from incremental theories

An implicit theory of ability approach to motivation argues that students who believe traits to be malleable (incremental theorists), relative to those who believe traits to be fixed (entity theorists), cope more effectively when academic challenges arise. In the current work, we integrated the implicit theory literature with research on top dog and underdog status to predict self-efficacy in an academic context. To examine our predictions, we assessed college students’ (N  =  165) implicit theories of mathematical ability and manipulated their underdog versus top dog status in a math competition. We hypothesized that holding an incremental (vs. entity) theory would interact with competition status (underdog vs. top dog) to predict mathematical self-efficacy. When in an underdog position, incremental (vs. entity) theories boosted students’ mathematical self-efficacy. Moreover, a mediated moderation model revealed that the experience of less helplessness accounted for greater self-efficacy in mathematical ability among academic underdogs with incremental (vs. entity) theories. Implications for teaching practices are discussed.     

A mental-health locus of control scale

The purpose of this study was to develop and seek initial validation of a mental- health locus of control scale. Twenty-six mental-health professionals rated each of the 14 statements of a previously-designed mental-health service request form along a 5-point locus of control scale. Six of the 14 items met the study's criteria for inclusion in the mental-health locus of control scale. Discriminant validity of the scale was provided by a study demonstrating that psychotic patients were more external in their perceived locus of control than were a nonpsychotic patient comparison group. Other validation studies and research are suggested.     

ESCAPE AS A FACTOR IN THE AGGRESSIVE BEHAVIOR OF TWO RETARDED CHILDREN

This study sought to identify some of the variables controlling the severely aggressive behavior of two retarded children. In Experiment 1, each child was presented with several demand and nondemand situations. Aggression was frequent in the demand situations and rare in the nondemand situations. When a stimulus correlated with the termination of demands was introduced, aggression fell to a near zero level. In Experiment 2, for one child, a variety of preferred reinforcers was introduced into the demand situation contingent on correct responding. Aggression abruptly decreased to a low level. Experiments 3 and 4 involved the second child. In Experiment 3, this child was permitted, in one condition, to leave the demand situation if he emitted a nonaggressive response. Aggression decreased to a low level. In Experiment 4, he was prevented, in one condition, from leaving the demand situation in spite of high levels of aggression. Aggression fell to a near zero level. In Experiments 3 and 4, he was permitted, in several conditions, to leave the demand situation following aggressive behavior. Aggression increased to a high level. The results suggested that: (1) aggression can sometimes function as an escape response; and (2) escape-motivated aggression can be controlled by: (a) introducing strongly preferred reinforcers to attenuate the aversiveness of the demand situation; (b) strengthening an alternative, nonaggressive escape response; or (c) using an escape-extinction procedure.     

The Social Psychology of Tanning and Sunscreen Use: Self-Presentational Motives as a Predictor of Health Risk1

To the extent that many people seek and maintain a suntan because they believe it makes them more attractive, people who are particularly motivated to make good impressions on others or to be seen as physically attractive are at increased risk for skin cancer. This study examined cognitive, motivational, and attitudinal predictors of two factors that are associated with increased risk for skin cancer: engaging in behaviors that increase one's exposure to UV radiation and inadequate use of sunscreen. Self-presentational motives involving a concern for one's personal appearance and the belief that being tan enhances one's attractiveness were the strongest predictors of the degree to which respondents exposed themselves to natural and artificial sources of UV radiation. Sunscreen use was best predicted by knowing someone with skin cancer. Implications for attempts to promote safe-sun practices are discussed.