Familial correlates of sexually active pregnant and nonpregnant adolescents

The relationship of familial, demographic, and individual characteristics to the probability of pregnancy was examined among 124 sexually active adolescent females. Logistic regression analyses revealed that adolescent pregnancy status was a function of a combination of demographic and familial variables. Adolescents who were pregnant at the time of the study perceived their families as having low levels of family strength, perceived communication with parents as closed, came from homes characterized by family fragmentation (i.e., only one parent or no parent living in the home), came from low-income households, were unlikely to use any method of birth control, and were more likely to be married than their nonpregnant counterparts.     

Brightness contrast: a reinterpretation of compound cue and combined cue experiments with pigeons.

A group of three pigeons was trained on a 4-ply multiple schedule: a green color and a vertical line superimposed upon an achromatic background as positive stimuli, and a red color and a horizontal line on an achromatic background as negative stimuli. The pigeons were tested with the vertical line superimposed upon different achromatic background intensities, then with the vertical line superimposed upon different green background intensities, and finally with the vertical line and its training achromatic backgfound attenuated (and unattenuated) by a neutral density filter. The gradients peaked at the luminance of the achromatic background used during training and at the equivalent luminance for the green background when it was substituted for the achromatic background. The brightness contrast, not the background luminance, was the critical variable as the neutral density filter attenuated both the line and the background equally, leaving brightness contrast unchanged; there was no response decrement to this attenuated stimulus. Two other groups of three pigeons showed that they attended to line orientation as well as to brightness contrast. The brightness contrast hypothesis was extended to explain results of attention experiments and combined cue experiments which have used line stimuli in combinations with different backgrounds.     

The role of ego-identity status in mating preferences

This study was designed to examine the role ego-identity plays in the mating preferences of late adolescents. In addition to examining the variance in mating preferences explained by ego-identity status, it was hoped that the results could assist in testing the competing Sexual Strategies (Buss & Schmitt, 1993) and Social Role (Eagly & Wood, 1999) theories. Ego-identity and the sex of the participant accounted for a significant amount of variance in the number of sexual partners desired and the penchant for short-term mating. The sex of the participant was the lone predictor of the importance placed on the mate characteristics of physical attractiveness and earning capacity with females placing more emphasis on the former and males placing more emphasis on the latter characteristic.     

LEX I and II: Two databases of surface word forms for psycholinguistic research in Spanish

Two databases of Spanish surface word forms are presented. Surface word forms are words considered as orthographically or phonologically specified without reference to their meaning or syntactic category. The databases are based on the productive written vocabulary of children between the ages of 6 and 10 years. Statistical and structural information is presented concerning surface word-form frequency, consonant-vowel (CV) structure, number of syllables, syllables, syllable CV structure, and subsyllabic units. LEX I was intended to aid in the study of reading processes. Entries were orthographic surface word forms; words were divided in their components following orthographic criteria. LEX II was designed for spoken language research. Accordingly, words were transcribed phonologically and phonological criteria were applied in extracting the internal units. Information about stress location was also provided. Together, LEX I and LEX II represent a useful tool for psycholinguists interested in the study of people acquiring Spanish as a first or foreign language and of Spanish-speaking populations in general.     

Grade, pubertal status, and gender-related variations in conflictual issues among adolescents

The purpose of this study was to describe adolescent perceptions of conflictual family issues, and to ascertain if the intensity of these issues is associated with adolescent grade in school, pubertal status, and gender. The sample was comprised of 279 junior high and senior high school students. Each participant completed a self-report measure of pubertal status, a demographic questionnaire, and the Issues Checklist. Principal factor analysis with varimax rotation of the Issues Checklist resulted in the retention of four factors accounting for 71.59% of the variance. Stepwise regression analyses were conducted for each emergent factor with grade in school, pubertal status, and gender serving as predictors. The results of these analyses indicated that the intensity of School Issues and Household Behavior Issues is greater among seventh and ninth graders than among eleventh graders. Self-Responsibility Issues were perceived as being most intense among transpubertal adolescents. Finally, boys perceived more intense conflict over Persistent Issues and Concerns than did girls.     

Partial reinforcement and autoshaping of the pigeon's key-peck behavior

Pigeons were exposed to continuous and partial reinforcement (25%) schedules in an autoshaping procedure. The number of trials and/or pairings per session were equated across two factorial group sets and all groups were trained for a fixed total number of acquisition trials (192). When acquisition was analyzed as a function of reinforcements delivered, the groups receiving fewer number of trials per session acquired the response faster, independently of the percentage of reinforced trials. Moreover, the number of reinforcements to satisfy an acquisition criterion was a monotonic function of the number of trials per session but not of the schedule. The results are discussed in relation to the neocontinuity and the scalar expectancy theories.     

Social context shapes cognitive abilities: associative memories are modulated by fight outcome and social isolation in the crab Neohelice granulata

Animal Cognition - Cognitive abilities of an animal can be influenced by distinct social experiences. However, the extent of this modulation has not been addressed in different learning scenarios:...     

Predictors of responses to stress among families coping with poverty-related stress

This study tested how poverty-related stress (PRS), psychological distress, and responses to stress predicted future effortful coping and involuntary stress responses one year later. In addition, we explored age, sex, ethnicity, and parental influences on responses to stress over time. Hierarchical linear modeling analyses conducted with 98 low-income families (300 family members: 136 adults, 82 school-aged children, 82 adolescents) revealed that primary control coping, secondary control coping, disengagement, involuntary engagement, and involuntary disengagement each significantly predicted future use of that response. Primary and secondary control coping also predicted less maladaptive future responses to stress, while involuntary responses to stress undermined the development of adaptive responding. Age, sex, and interactions among PRS and prior coping were also found to predict certain responses to stress. In addition, child subgroup analyses demonstrate the importance of parental modeling of coping and involuntary stress responses, and warmth/nurturance and monitoring practices. Results are discussed with regard to the implications for preventive interventions with families in poverty.