Are college students adults? Their conceptions of the transition to adulthood

College students (N=346) were surveyed on their conceptions of the transition to adulthood and their own status as adults. Only 23% indicated that they considered themselves to have reached adulthood, while nearly two-thirds indicated that they considered themselves to be adults in some respects but not in others. The most important criteria for marking the transition to adulthood were indicated to be individualistic and intangible criteria, particularly accept responsibility for the consequences of your actions, decide on beliefs and values independently of parents or other influences, and establish a relationship with parents as an equal adult, each of which was endorsed by more than 70% of the sample. In contrast, role transitions such as completing education, marriage, and becoming a parent were endorsed by less than 20%. It is suggested that the transition from adolescence to adulthood in Western societies is a process that may last many years, during which individualistic and intangible markers of adulthood (such as those specified here) are gradually and incrementally pursued.     

Adaptive Dynamics of the Leg Movement Patterns of Human Infants: II. Treadmill stepping in Infants and Adults

Infant treadmill steps have many temporal and kinematic similarities to adult walking. Kinematic similarities can result from different patterns of underlying torque, however. In this study, we used inverse dynamics to compare the patterns and contributions of active (muscle) and passive (gravity and motion-dependent) torques in the swing phase of treadmill stepping in 7-month-old infants and adults. Results indicated that adults consistently used muscle torque to initiate and terminate swing, but that passive torques accounted for leg motion during most of the swing phase. Infants, in contrast, displayed multiple patterns of torque contributions during swing. In the most frequently occurring infant pattern, muscle torque remained flexor throughout swing and joint reversals were due to the dominant passive gravitational torque. The kinetic data suggest that the temporally and kinematically similar treadmill steps produced by adults and infants do not emanate from a unique set of neural commands to the muscles, but from a flexible interplay between multiple internal as well as external elements. These data suggest that the intrinsic dynamics of the human system provide a medium out of which, given a supportive context, stable patterns can emerge spontaneously. During development, voluntary controlled movement patterns must build on these intrinsic dynamics.     

Adaptive Dynamics of the Leg Movement Patterns of Human Infants: III. Age-Related Differences in Limb Control

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.     

Student evaluation of sex education programs advocating abstinence.

This research examined the attitudes of students who were enrolled in three different sex education programs that emphasize abstinence. Data were examined to determine whether secondary school students responded positively to the programs. The programs examined were Values and Choices, Teen Aid, and Sex Respect. Results of the study indicated that all three programs were rated positively, with female, younger (junior high school age), and virgin-naive students rating the programs more highly.     

A somatosensory latency between the thalamus and cortex also correlates with level of intelligence

As part of a study on speed of information processing and intelligence, 205 young adult postsecondary students were tested for somatosensory evoked potential (SEP) latencies and intelligence. Following stimulation at the wrist, latencies of three SEPs were determined: N13, generated in the cervical spinal cord/medulla region; N19, generated in the thalamus; P22, generated in the arm region of the somatosensory (parietal) cortex. These latencies and two latency differences, N19 - N13 and P22 - N19, were tested for correlation with a nonverbal measure of intelligence; only P22 - N19 significantly correlated (r = −.217; P = .013, two-tailed). Comparing this latency difference in students in the first IQ quartile (mean IQ = 103.4) with that of students in the fourth quartile (M = 131.2) showed mean differences of 4.13 ms versus 3.21 ms, respectively (p = .0034, two-tailed).P22 - N19 measures time for signal transmission from the thalamus to the sensory cortex. These results agree with considerably more extensive data on visually evoked potentials showing a negative correlation between IQ and the latency for a visual stimulus of the retina to produce a signal at the visual cortex (most of this latency is between the thalamus and the cortex; Reed & Jensen, 1992). The findings here agree with the visual results and strongly suggest that the IQ-latency correlation occurs because the latency indexes cortical nerve conduction velocity, an important component of information processing speed.     

Variations on the vertical jump: individual adaptations to changing task demands

Here we explored the coordination of joint behaviors exhibited during the vertical jump and variations of that jump. By manipulating the take-off angle, we required an adjustment to changing task demands. It was hypothesized that kinematic features of the jump would change but that spatiotemporal relationships essential to propulsion would remain invariant across all conditions. To test this hypothesis, six adult male subjects performed jumps at six different take-off angles. An analysis of cinematographic data revealed that individual subjects changed the sequence and timing of lower-extremity joint reversals. In contrast, the covariation of joint behaviors during the propulsive phase and the timing of maximum intersegmental extension velocities were extremely stable within each individual across changes in task. We argue that the flexibility to alter sequence and timing is part of a strategy that permits adaptation to the context and facilitates a continued coordination among variables associated with propulsion.     

Spatial learning in the rat: impairment induced by the thiol-proteinase inhibitor, leupeptin, and an analysis of [3H]glutamate receptor binding in relation to learning

Rats were given continuous intraventricular infusion of saline or the thiol-proteinase inhibitor leupeptin, via subcutaneously implanted osmotic minipumps, while being trained on a spatial learning water task using spaced trials. Leupeptin caused overnight forgetting during training, but performance eventually reached asymptote in both groups. A retention test conducted 48 h later to assess spatial memory revealed no significant group differences, but did cause, in saline-treated rats only, a disruption of subsequent retraining back to the correct spatial location. The groups showed no differences in Cl-dependent [3H]glutamate receptor binding to hippocampal or entorhinal cortex membranes subsequent to training. In a second experiment, normal rats trained on the same task also showed no differences in Cl-dependent [3H]glutamate binding relative to rats exposed to the water task but given random spatial position training and handled controls. The results are discussed in relation to the hypothesis of Lynch and Baudry (Science (1984) 224, 1057-1063) that a calcium-dependent thiol proteinase is involved in memory formation through its ability to modify glutamate receptor distribution and dendritic spine shape.     

The Structure of Affect in a Non-Western Culture: Evidence for Cross-Cultural Comparability

We investigated the structure of affect in the Filipino culture and compared our results to those in Western studies. Four samples of students (ns = 397 to 530) rated their mood for today, the past week, or in general, using near-comprehensive sets of Filipino mood adjectives. Results of exploratory and confirmatory factor analyses supported a hierarchical model of affect and the cross-cultural comparability of self-report mood dimensions (i.e., higher-order Positive and Negative Affect, plus specific affects corresponding to hypothesized universal or basic emotions). The results were more consistent with biological theories of affect than a strong social constructivist perspective.     

Features of Interview Questions Associated with Attenuation of Symptom Reports

Previous studies have suggested that discrepant reporting in a test–retest reliability paradigm is not purely random measurement error, but partly a function of a systematic tendency to say no during retest to questions answered positively at initial testing (attenuation). To examine features of interview questions that may be associated with attenuation, three raters independently assessed the structural and content features of questions from the Diagnostic Interview Schedule for Children (version 2.3) and linked these to data from a test–retest reliability study of 223 community respondents (parent and child reports). Results indicated that for both parent and youth reports, item features most strongly associated with attenuation were (a) being a stem question (asked of all respondents, regardless of any skip structure); (b) question placement in the first half of the interview; (c) question length; (d) question complexity; or (e) requiring assessment of the timing, duration, or frequency of a symptom. Findings may be explained by participants' conscious efforts to avoid further questions or by their learning more about the nature and purpose of the interview as they gain more experience; alternatively, findings may represent a methodological artifact of structured interview design.