Self-concept and attraction for similar and dissimilar others.

The present study investigated the role of self-concept as a moderator of the similarity-attraction relationship described by Byrne. Subjects conducted face-to-face interviews with confederates who played roles as job applicants. Similarity-dissimilarity was manipulated by the confederate roles as well as by the information given the subjects in accordance with the procedures described by Byrne. The hypothesis was tested and confirmed that persons with favorable self-concepts would be more attracted to others with similar attitudes than to others with dissimilar attitudes. Persons with negative self-concepts did not show a preference for similar others. It was suggested that earlier studies in this area suffered from methodological flaws and did not constitute an adequate test of the hypothesis. Suggestions for future work in the area were given.     

Partial reinforcement effects in classical aversive conditioning in rabbits and human beings.

The partial reinforcement extinction effect (the PREE) in classical aversive conditioning was investigated in 2 experiments. In the first, the nictitating membrane responses of 120 rabbits were conditioned at a 250-msec. interstimulus interval (ISI) under continuous reinforcement, partial reinforcement with the unconditioned stimulus (US) omitted (Group PO), or partial reinforcement with the US delayed to 1,500 msec. (Group PD). These 3 groups were factorially extinguished under US-Omitted, US-Unpaired, or US-Delayed extinction regimens. A significant PREE was obtained, but only for PO training and US-Omitted extinction. The second experiment, employing human subjects in a masked eye blink conditioning task, produced parallel results. A general discrimination view of the classical PREE seems applicable, but one in which neither cognitive factors nor intertrial conditioning of reinforcement aftereffects play a significant role.     

On differentiating syntactic and semantic features in emerging grammars: Evidence from empty form usage

Recent emphasis on underlying semantic relations in the child's acquisition of grammar has left ignored those cases where syntactic operations can be observed relatively independent of semantic relations. Such operations may reveal optional processes in the child's transition from single-word utterances to grammatical usage that may be related to specific linguistic rather than general cognitive abilities.     

The Effect of the Physical Attractiveness and Role of the Helper on Help Seeking

The effects of a helper's physical attractiveness and role on help-seeking behavior were investigated here. Eighty randomly selected Smith College students were the subjects; the helpers were two confederates selected on the basis of a separately conducted photograph evaluation. The confederate was designated either as an experimenter (Role condition) or as a fellow subject (Nonrole condition). Subjects were reluctant to ask the attractive confederate for help when she was in the Nonrole condition; rather, most in this condition asked for information instead of assistance. When the confederate was unattractive, more subjects asked for help when she was in role than when she was not. Although there was a significant main effect, most of this effect appears to be accounted for by the low rate of seeking help in the Attractive, nonrole condition. Subjects took longer to communicate with the attractive confederate than with the unattractive one; further, they reported feeling more uncomfortable in the presence of the attractive helper regardless of role.     

Interactive effects of deprivation in the albino rat

The interactive effects of feeding and drinking schedules were investigated in three experiments. Twenty-four hour water-deprived rats consumed their entire obligatory water intake prior to feeding, whereas 24-hr food-deprived rats consumed only small quantities of food prior to drinking. This drinking was apparently due to a shift of water stores rather than an actual negative water balance. Experiment 3 investigated the effects of 24, 48, or 72 hr of water, food, or total deprivation. Water-deprived rats did not adequately suppress food intake and became thirstier than totally deprived rats. The effects of total deprivation were essentially identical to those of food deprivation. These experiments indicate the degree to which deprivation schedules impose restrictions on the reinforcement parameters of behavioral experiments.     

Learned taste aversions in rats as a function of delay,speed, and duration of rotation

Rats fed a saccharin solution and then rotated on a turntable showed an aversion to the saccharin solution on later testing. In the first experiment, the rats learned to avoid saccharin with delays of as much as 9 hr between drinking the saccharin and the start of rotation. The second experiment showed that the critical determinant of aversiveness of rotation was number of rotations. The rats avoided saccharin as much after rotation at high speeds for short durations as after rotation at low speeds for long durations.     

Increment thresholds against pulsed and steady backgrounds

Cornsweet and Pinsker reported that ΔL/L was constant at all values of L for briefly pulsed fields (ΔL was the luminance increment required for discriminating which of two nearby flashed fields was brighter). We obtain the same result when the subject must detect which of two briefly (4-msec) flashed backgrounds contains an increment at its center. However, when the background and increment are flashed at a longer duration (200 msec) ΔL/L decreases with increasing L as is obtained with a steady background. Two previous models which handle earlier work do not readily accommodate this result; we suggest a theoretical approach that does.