Effects of Visual Representation on Social Influence in Computer‐Mediated Communication

Two experiments investigated if and how visual representation of interactants affects depersonalization and conformity to group norms in anonymous computer‐mediated communication (CMC). In Experiment 1, a 2 (intergroup versus interpersonal) × 2 (same character versus different character) between‐subjects design experiment (N= 60), each participant made a decision about social dilemmas after seeing two other (ostensible) participants’ unanimous opinions and then exchanged supporting arguments. Consistent with the Social Identity model of Deindividuation Effects (SIDE), when the group level of self‐identity was rendered salient in an intergroup encounter, uniform virtual appearance of CMC partners triggered depersonalization and subsequent conformity behavior. By contrast, when the personal dimension of the self was salient, standardized representation tended to reduce conformity. To elucidate the mediation process, Experiment 2 investigated the causal links between depersonalization, group identification, and conformity. The results show that depersonalization accentuated adherence to group norms, both directly and indirectly via group identification.     

Delayed-matching-to-sample by marsh tits and great tits

The ability of two species of tits to remember the location and/or features of an object was tested in a delayed-matching-to-sample procedure. Three values of retention interval between presentation of the sample stimulus and the choice--30 sec, 5 min, and 15 min--were used. Both species performed at above-chance level at all retention intervals, and there was no significant decline in accuracy with increasing interval. A pool of 100 stimulus objects was used, but the results of control trials indicated that the birds responded primarily to location rather than stimulus features of the object itseif. Although the food-storing marsh tit tended to perform at a higher level than the non-storing great tit, the only significant difference between the species was in the first 50 trials of the first treatment, when the birds were acquiring the task. The results are discussed in relation to the hypothesized special memory capacity of food-storing birds.     

A comparison of the effects of partial reinforcement schedules using a within-subject serial autoshaping procedure

Three experiments, each using a single group of pigeons, are reported. In Experiment 1 subjects were initially trained with two stimuli, one of which was always followed by food, the other being reinforced according to a 50% partial reinforcement schedule. Subsequently a serial procedure was adopted in which an additional stimulus, C, was consistently followed by the partially reinforced CS. A second additional stimulus, A, was followed on half of its occurrences by the continuously reinforced CS, its remaining presentations being followed by nothing. The rate of autoshaped keypecking was substantially greater during A than during C. In the remaining experiments subjects received first-order conditioning with a single stimulus that was either partially (Experiment 2) or continuously (Experiment 3) reinforced. The stimuli A and C were then again introduced for serial autoshaping. Stimulus A was occasionally paired with the CS and occasionally followed by nothing, whereas stimulus C was always followed by the CS. As in Experiment 1, the rate of responding during A was greater than during C. It is proposed that one influence on the rate of autoshaped keypecking during a CS is the accuracy with which the immediate consequences of that CS are predicted.