Needs (Murray, 1938) and state-variables (Skinner, 1938).

Skinner's concept of drive as a state-variable and his powerful rationale for introducing it agree closely with Murray's treatment of need. Operant behaviorists' usual deprecation of motivation in favor of stimulus control arises partly from features of parameters, insufficiently explored in some regions, of Skinner box research. For human adults on rich reinforcement schedules, response selection is chiefly controlled by the regnant motive. Skinner's life-long interest in inner events and translating psychodynamic concepts into behaviorese was obscured by his metalanguage philosophy of science (behaviorism).     

A study of orientation errors in response to Kohs-type figures(1)

In order to elucidate the nature of the orientation errors encountered when subjects are required to reproduce Kohs-type figures, subjects drawn from a culture where such errors are reported to be relatively common were required to reproduce orientation of simple figures. It was found that the responses made in the case of square figures showed a definite drift towards a “stable” orientation; the drift observed in the case of circular stimuli was too weak to permit an unambiguous interpretation. The relevance of these data to previous data on cross-cultural differences in responses to Kohs-type stimuli is briefly examined.     

Ravens (Corvus corax) are indifferent to the gains of conspecific recipients or human partners in experimental tasks

Although cooperative behaviours are common in animals, the cognitive processes underpinning such behaviours are very likely to differ between species. In humans, other-regarding preferences have been proposed to sustain long-term cooperation between individuals. The extent to which such psychological capacities exist in other animals is still under investigation. Five hand-reared ravens were first tested in an experiment where they could provide food to a conspecific at no cost to themselves. We offered them two behavioural options that provided identical amounts of food to the actor and where one of the two options additionally delivered a reward to a recipient. Subsequently, we made the ravens play a no-cost cooperation game with an experimenter. The experimenter had the same options as the animals and matched the ravens’ choices, making the prosocial choice the more profitable option. In both conditions, ravens were indifferent to the effects of their choices and hence failed to help conspecifics and to cooperate with the experimenter. While our negative results should be interpreted with care, overall, our findings suggest that the ravens had no understanding of the consequences of their actions for a potential recipient. This study adds to several others that have used a similar set-up and have reported negative results on other-regarding preferences in animals.     

The effects of errors on children's performance on a circle-ellipse discrimination

Children first learned by means of a teaching program to discriminate a circle from relatively flat ellipses. Children in the control group then proceeded into a program which gradually reduced the difference between the circle and the ellipses. They advanced to a finer discrimination when they made a correct choice, and reversed to an easier discrimination after making errors ("backup" procedure). The children made relatively few errors until they approached the region of their difference threshold (empirically determined under the conditions described). When they could no longer discriminate the forms, they learned other bases for responding that could be classified as specifiable error patterns. Children in the experimental group, having learned the preliminary circle-ellipse discrimination, were started at the upper end of the ellipse series, where it was impossible for them to discriminate the forms. The backup procedure returned them to an easier discrimination after they made errors. They made many errors and reversed down through the ellipse series. Eventually, most of the children reached a point in the ellipse series where they abandoned their systematic errors and began to make correct first choices; then they advanced upward through the program. All of the children advanced to ellipse sizes that were much larger than the ellipse size at the point of their furthest descent.     

Effects of increment size and reinforcer volume on progressive ratio performance

The progressive ratio schedule requires the subject to emit an increasing number of responses for each successive reinforcement. Eventually, the response requirement becomes so large that the subject fails to respond for a period of 15 min and thereby terminates the session. This point is arbitrarily defined as the “breaking point” of the subject's performance. The measure is quantified in terms of the number of responses in the final completed (i.e., reinforced) ratio run of the session. Previous work has shown that this measure varies as a function of several motivational variables and may thus be useful as an index of reinforcement strength. The present study is an extension of that work. The subjects were four rats. In the first experiment, the effects of the size of the increment by which each ratio run increased were studied. In two additional experiments, the volume of a liquid reinforcer was varied using both large and small ratio increments. The results indicate that the number of responses in the final completed ratio run increases as a function of the size of the ratio increment. However, the number of reinforcements obtained by the animals per session declines sharply. When large ratio increments are used, the number of responses in the final ratio increases as a function of the volume of the reinforcer, but when small increments are used, progressive satiation results in a decline in performance with the larger volumes of liquid.     

Probability of directional errors with disordinal (qualitative) interaction

In a factorial design with two or more factors, there is nonzero interaction when the differences among the levels of one factor vary with levels of other factors. The interaction is disordinal or qualitative with respect to a specific factor, sayA, if the difference between at least two levels ofA is positive for some and negative for some levels of the other factors. Using standard methods of analysis, there is a potentially large probability of drawing incorrect conclusions about the signs of differences in the presence of disordinal interaction. The maximum probability of such incorrect conclusions, or directional errors, is derived for two-factor designs in which the factor of interest has two levels and the number of levels of the other factor varies.     

Further validation of the Maudsley Marital Questionnaire (MMQ)

This study examined the Factor structure and internal consistency of the Dutch version of the Maudsley Marital Questionnaire (MMQ) for a sample of 787 respondents in Belgium. Principal components analysis, followed by varimax orthogonal rotation, identified the expected three factors (M - Marital, S - Sexual, GL - General Life), which jointly explained 53% of the variance. The Cronbach alpha for MMQ - M (.90) and MMQ - S (.80) were of high value while for MMQ - GL (.66) was lower. The MMQ scales were found significantly correlated with each other: M - S, .60; M - GL, .46 and S - GL, .33.