On coalition formation in simple games: A mathematical analysis of Caplow's and Gamson's theories

In this paper, we propose a theory of coalition formation in simple games. The process of coalition formation is modeled as an abstract game. Two solutions of abstract games, the core and the dynamic solution, are used as the predictions of our model. Two classical theories of coalitions in sociology due to Caplow and Gamson are reformulated in a more general and mathematical setting. These theories are then analyzed using the techniques of our theory.     

Stimulus and response contributions to the children's reaction-time repetition effect

Adults and 8-, 10-, 12-, and 14-year olds completed a serial reaction-time task with two stimuli mapped to each of two responses and 100-, 500-, and 1000-msec response-stimulus intervals (RSIs). Trials were classified as (1) identical (same stimulus and same response on two consecutive trials), (2) response equivalent (different stimulus but same response on two consecutive trials), or (3) different (different stimulus and different response on two consecutive trials). Identical and different trials were compared as a general indication of repetition effects. Response-equivalent minus identical reaction time identified stimulus contributions, and different minus response-equivalent reaction time identified response contributions. Adults received a repetition advantage at all RSIs and children received a repetition advantage at 500- and 1000- but not 100-msec RSIs. Stimulus contributions accounted for the repetition effect for both adults and children. At the 500- and 1000-msec RSIs, both the overall repetition effect and stimulus contribution were positive and decreased in magnitude as age increased. The response contribution was independent of RSI and was negative for 8- and 10-year-olds and near zero or positive for older performers. At the longer RSIs, positive stimulus contributions were sufficient to overcome the negative response contributions present for younger children.     

On signalling that it's your turn to speak

The operation of a “speaker-state signal” in two-person, face-to-face conversations is hypothesized. Display of this signal by an auditor appears to indicate, among other things, that he is claiming the speaking turn, differentiating this action from a “back-channel behavior” by which he merely acknowledges some portion of the speaker's message. The signal also appears to play a part in the resolution of situations in which both participants simultaneously claim the speaking turn. The signal is defined as the display of at least one of a set of four behavioral cues, two in paralanguage and two in body motion.     

Blocking acquisition of the rabbit's nictitating membrane response to serial conditioned stimuli

Three experiments demonstrated that prior training with one stimulus (CS1) would block acquisition of the rabbit's nictitating membrane response (NMR) to another stimulus (CS2) which was more contiguous to the US during serial compound training (CS1-CS2-US). Specifically, the CS1-US interval was 800 msec, which produces only a modest rate of CR acquisition, while the CS2-US interval was 400 msec, which is an optimal value for the NMR preparation. Experiment 1 demonstrated blocking when CS1 overlapped CS2, and Experiment 3 demonstrated blocking when CS1 and CS2 were presented in a strictly sequential fashion. Experiment 2 showed that the magnitude of blocking in the serial compound was comparable to that obtained in a simultaneous compound in which both the CS1-US and CS2-US intervals were 800 msec, thus making CS2 less contiguous with the US than in the serial compound. Moreover, the level of responding to CS2 in all serial compound groups (blocking and control) was lower than in the simultaneous compound groups. The present findings provide further evidence that the associative consequences of CS-US contiguity can be highly attenuated by processes of attention or competition for associative strength.     

On throwing out the baby with the bathwater: A reply to Black and Wilensky's evaluation of story grammars

A number of criticisms of a recent paper byare made. (1) In attempting to assess the observational adequacy of story grammars, they state that a context-free grammar cannot handle discontinuous elements; however, they do not show that such elements occur in the domain to which the grammars apply. Further, they do not present adequate evidence for their claim that there are acceptable stories not accounted for by existing grammars and that the grammars will accept nonstories such as procedures. (2) They state that it has been proven that under natural conditions children cannot learn transformational grammars, which is a misrepresentation of the learnability proofs which have been offered. (3) Most important, they take an unduly narrow approach to story understanding by claiming that people only understand story content and do not have knowledge of story structure which is useful in comprehension or memory. Counterevidence from the literature is cited which indicates that such knowledge is both useful and used, and a number of methods for assessing the psychological adequacy of structural models are discussed.     

Humphreys's attenuated test of Spearman's hypothesis

Humphreys's test of Spearman's hypothesis (viz., that the size of the standardized black-white differences on various psychometric tests is positively related to the tests' loadings on g, the general intelligence factor) is methodologically weak. It is based on comparison of a fairly representative sample of the black population of U.S. school children with a highly selected sample of the white school population, representing the lowest 15 to 20% of whites in socio-economic status (SES). A fair test of the hypothesis requires that the black and white samples should not be selected on any g-correlated variable, such as SES. Selection attenuates and distorts the relationship between tests' g loadings and the magnitude of the standardized mean black-white differences on the tests. Other unorthodox conditions in Humphreys's study, such as performing factor analysis on the test-score means of various arbitrary demographic groups instead of on individual test scores inflates tests' g loadings and biases the test of Spearman's hypothesis by restriction of reliable variance in g loadings. Humphreys's study cannot be considered a proper replication of Jensen's examination of Spearman's hypothesis in 11 different studies comprising 74 different tests, which consistently bears out Spearman's hypothesis.     

Interpreting inclusion: A contribution to the study of the child's cognitive and linguistic development

Six experiments are reported which examine the young child's ability to compare included and nonincluded sets. Results indicate that with certain forms of task presentation most 3- to 5-year-old children can compare part with whole. Further, errors which occur in inclusion tasks are similar to errors which occur in tasks involving comparison of nonincluded sets. Thus young children can solve inclusion problems, and their customary failure to do so does not arise because the problem requires comparison of a whole with an included part. Employing a distinction between intended tasks (those which the adult wishes the child to complete) and received tasks (those which the child, in fact, completes) the studies indicate how linguistic and perceptual aspects of the presented information may interact with the child's assumptions about the nature of the task to be completed.