Does nutrition cause intelligence? A reanalysis of the Cali experiment

Recent literature has suggested there is a causal link between malnutrition and impaired cognitive development. From a selective review of this literature it is concluded that owing to methodological imperfections in many of these studies the presence or absence of such a link cannot be established, even if randomized experiments were to be carried out. It is argued that compensatory experiments, even though they are not as logically compelling as experiments where proper nutrition is withheld, are ethically justifiable and more useful strategically since they may suggest ways of improving the cognitive development of currently affected children, especially if a variety of compensatory treatments is implemented. A reanalysis of such an experiment was conducted to determine whether the nutritional or educational component of the treatment was responsible for the observed gains in cognitive development. The reanalysis indicated that after four years of treatment there was no association between cognitive and nutritional status. The results were discussed in relation to previous research. Some of the social implications of the results were also discussed.     

Evaluating competence of women and men: Effects of marital and parental status and occupational sex-typing

A sample of 160 female and male college students read a completed job application and a letter written by the applicant. The job was in either a feminine or a masculine field. The applicant was described as either female or male, single or married, and having one or no children. Subjects answered seven evaluative questions about the competence of the applicant and the merits of the letter. Women, especially single ones, who applied for a sex-typical job generally were evaluated most favorably. Men, especially single ones, and women who applied for sex-atypical jobs were evaluated least favorably.     

Black Students' Reactions to Feedback Conveyed by White and Black Teachers1

The present investigation examined some processes mediating self-fulfilling prophecies among black students. Specifically, we hypothesized that feedback conveyed by black and white teachers would differentially influence black students' perceptions of how the teacher viewed their success/failure, effort, ability, luck and task difficulty. In addition, we hypothesized that negative feedback would affect perceptions of evaluations differently than positive feedback. Ninety black undergraduates participated in an experiment in which a black or white teacher (confederate) expressed one of five evaluative feedback responses to a student's score on an analogies test. The results provided partial support for the first hypothesis: black female students perceived white teachers as assessing their performance less positively: that is, they perceived them to underestimate their ability and the difficulty of the task. Negative feedback also led students to believe the teacher held an unfavorable but inaccurate impression of their ability and effort, and that the teacher underestimated the difficulty of the task. These findings suggest that black students—black females in particular—may assume that white teachers hold less favorable assessments of them than black teachers and all students may be sensitive to negative evaluations.     

Effects of household sex composition on the salience of one's gender in the spontaneous self-concept

It was hypothesized that being a boy or a girl becomes more salient in a child's self-concept to the extent the other sex numerically predominates in the child's household. This prediction was based upon an information-processing, distinctiveness postulate that a person contemplating a complex stimulus (such as the self) selectively notices and encodes its more distinctive, information-rich aspects. The spontaneous self-concept elicited by nondirective “Tell us about yourself” interviews of 560 school children were scored for spontaneous mention of one's gender. As predicted, boys spontaneously mentioned their maleness more often when they came from households where females were in the majority; girls mentioned their femaleness more often when from households with male majorities; boys mentioned their maleness more often when from father-absent than from father-present homes. Incidental findings are that gender is more salient in the negation self-concept (“Tell us what you are not”) than in the affirmation self-concept (“Tell us about yourself”) especially for girls and that gender becomes increasingly salient as the child grows older.     

Central sources of visual masking: Indexing structures supporting seeing at a single,brief glance

Summary When two briefly exposed, spatially overlapping visual fields are presented dichoptically, the identifiability of the first field is a J-shaped function of the interval separating their onsets. Three distinct sources of central masking are inferred from the selective influence of variables at different onset asynchronies. In integration through common synthesis, two fields presented at or near simultaneous onset yield one iconic representation. The distinctiveness of this source is inferred from the selective influence of eye dominance at and near simultaneous onset. At longer onset asynchronies, the selective influence of variables such as mask contrast and degree of contour overlap imply a second source of masking. This source was identified with the inhibition of sustained channels by transient channels reported elsewhere. Interchannel inhibition is proposed to affect the fidelity of the iconic representation, but here the imprecision is due to loss of form-relevant information on the first field. At yet longer onset asynchronies, where the fields are phenomenally separate, a third set of variables (e.g., words vs. nonwords and left vs. right visual fields) show their influence. These effects are taken as evidence of a replacement principle: the iconic representation of the second field directs attention from that of the first field. Here, first-field identifiability is constrained by time rather than by impoverished data.In a final series of experiments, central three-field interactions are demonstrated. A field, inserted into the temporal gap between two fields, is perceptually impaired even though it is separated from the first and third fields by intervals at which, individually, neither field is an effective mask. This second-field depression is accompanied by a first-field enhancement. The three sources of central masking are hard pressed to account for the three-field effects.     

Conservation training in four-year-old children

In Experiment 1 two training procedures were used to teach four-year-olds to conserve. Verbal rule instruction consisted of providing verbal rules and demonstrations of the operations referred to by the rules. Feedback consisted of providing verbal feedback contingent upon the children's responses. One week after training on conservation of number and length the children were given a posttest which included tests of conservation of number, length, and mass. Children who were given verbal rule instruction conserved significantly more on the number and length posttest problems than children who were not. However, this learning did not transfer to the mass problems, possibly because mass is not naturally acquired until some time after conservation of number and length. The feedback training procedure had no effect on conservation performance. In Experiment 2, the verbal rule instruction procedure was used to train four-year-olds on conservation of length and mass. One week after training the children were tested on both conservation of number, which is typically acquired before length and mass, and conservation of weight, which is typically acquired after length and mass, as well as on conservation of length and mass. Children who were given training conserved more on all four types of problems than children in the control group.