MENTAL ARITHMETIC IN AFRICA AND AMERICA: STRATEGIES,PRINCIPLES, AND EXPLANATIONS*

Mental arithmetic abilities were studied among unschooled African adults and American college students. A set of problems tested the use of the four basic arithmetic operations. Performance was analyzed for: strategies, implicit arithmetic principles, and explicit explanations of the principles. Both groups showed accurate mental arithmetic strategies related to the base ten structure of their native counting systems. The American students' mental strategies additionally made use of algorithms based on written place values. Several principles were implicit in the calculation strategies of both groups, and both used these principles to short-cut calculations. Though the African subjects did not, the American subjects did describe these abstract principles in explicit common language or algebraic expressions. Relationships between schooling and cognition are discussed.     

Cognitive styles in the development of medical careers

Recent research has shown that academic choice and achievement may be partly a function of the student's standing on the field-dependence-independence cognitive-style dimension. The results of two longitudinal studies suggest that information about field dependence-independence may be of value for student guidance in the medical setting. The first, a study of college undergraduates who early expressed an interest in medicine, showed that these cognitive styles play a discernible role in determining who will eventually enter medical school. The second, a study of medical students, showed that field-dependent and field-independent students subsequently tend to choose different medical specialties. These results are consistent with cognitive-style theory, which proposes that field-independent people will choose vocations that require cognitive restructuring skills, whereas field-dependent people will choose vocations that require greater social-interpersonal involvement.     

Responding to indirect speech acts

Indirect speech acts, like the request Do you know the time?, have both a literal meaning, here “I ask you whether you know the time,” and an indirect meaning “I request you to tell me the time.” In this paper I outline a model of how listeners understand such speech acts and plan responses to them. The main proposals are these. The literal meaning of indirect speech acts can be intended to be taken seriously (along with the indirect meaning) or merely pro forma. In the first case listeners are expected to respond to both meanings, as in Yes, I do—it's six, but in the second case only to the indirect meaning, as in It's six. There are at least six sources of information listeners use in judging whether the literal meaning was intended seriously or pro forma, as well as whether there was intended to be any indirect meaning. These proposals were supported in five experiments in which ordinary requests for information were made by telephone of 950 local merchants.     

The interactive effects of facial expressions of emotion and verbal messages on perceptions of affective meaning

The influence of facial expressions of emotion on perceptions of affective sentence meaning was investigated by pairing happy, angry, suprised, and sad faces of “teachers” with sentences of varying affective tone. Ninety-five students judged the overall meaning communicated by these paired stimuli. The design allowed exploration of unique facial-verbal combination effects, overall cue integration effects, and sex differences. Clear effects of cue combinations emerged. Perceived sincerity was found to be a function of the consistency of evaluative (positivity) but not dominance cues. Perceived positivity was an interactive function of both evaluative cues and dominance cues. Perceived dominance was affected by the interaction of evaluative cues. The subtleties of cue combination were clarified through open-ended dependent measures. Also, as expected, females were found to be more sensitive than males to verbal-nonverbal cue conflict in perceptions of sincerity. However, no other sex differences were found. The findings were discussed with regard to the need for a firm empirical base upon which to integrate verbal and nonverbal research traditions in the communication of affective meaning.     

Indirect social influence: Change in judgmental process or anticipatory conformity?

In three experiments, subjects imposed sentence in a criminal case before and after reading the harsh sentence imposed by the trial judge. They then read and imposed sentence in another case. In one experimental condition the subjects anticipated learning the judge's sentence in Case 2; in the other condition they were told not to anticipate learning the judge's sentence. Control subjects made their judgments without ever seeing the judge's sentence. Direct influence was the change in sentences within cases; indirect influence was the difference between initial sentences in Cases 1 and 2. Though direct influence was minimal and not significant, indirect influence was substantial, and was greater in the anticipation than no-anticipation than control conditions, indicating that both modification of the judgmental process and anticipatory conformity were operating. Indirect influence may then reflect a change of either type, depending on a number of methodological and other factors.     

An unlabeled bracketing solution to the problem of conjoined phrases in Montague's PTQ

Conclusions Although Montague claims that the system of The proper treatment of quantification in ordinary English includes some conjunction and disjunction, the rules for other grammatical constructions do not take conjunction or disjunction into account, and in general fail either syntactically or semantically when one of their arguments is so formed. Using an unlabeled bracketing of syntactic structure and recursive definitions, we have been able to rewrite the rules so that correct results are obtained.These results should provide a firmer basis for extension of PTQ.This research was supported in part by NSF Grants GS-31309 and BNS 76-23840. Our observations were made with the aid of several computer programs for PTQ: a sentence generator for the bracketed syntax, a parser, and a translator. I should like to thank Philip Tedeschi, David Warren, and David Lewis for helpful discussions. Warren is also acknowledged as co-author of the section on the semantic role of conjunction.     

Modeling semantic memory: Effects of presenting semantic information in different modalities

How is semantic information from different modalities integrated and stored? If related ideas are encountered in French and English, or in pictures and sentences, is the result a single representation in memory, or two modality-dependent ones? Subjects were presented with items in different modalities, then were asked whether or not subsequently presented items were identical with the former ones. Subjects frequently accepted translations and items semantically consistent with those presented earlier as identical, although not as often as they accepted items actually seen previously. The same pattern of results was found when the items were French and English sentences, and when they were pictures and sentences. The results can be explained by the hypothesis that subjects integrate information across modalities into a single underlying semantic representation. A computer model, embodying this hypothesis, made predictions in close agreement with the data.