The cost of collaboration: why joint decision making exacerbates rejection of outside information

Prior investigators have asserted that certain group characteristics cause group members to disregard outside information and that this behavior leads to diminished performance. We demonstrate that the very process of making a judgment collaboratively rather than individually also contributes to such myopic underweighting of external viewpoints. Dyad members exposed to numerical judgments made by peers gave significantly less weight to those judgments than did individuals working alone. This difference in willingness to use peer input was mediated by the greater confidence that the dyad members reported in the accuracy of their own estimates. Furthermore, dyads were no better at judging the relative accuracy of their own estimates and the advisor's estimates than individuals were. Our analyses demonstrate that, relative to individuals, dyads suffered an accuracy cost. Specifically, if dyad members had given as much weight to peer input as individuals working alone did, then their revised estimates would have been significantly more accurate.     

Mere repeated exposure and experimental stress as determiners of stimulus evaluations

From Berlyne's theorizing concerning the determinants of hedonic value of a stimulus it was hypothesized that importance of evaluative judgments and frequency of exposure would interact in determining the favorability of affective ratings. This prediction was confirmed by the data. Increasing the importance of the rating task decreased the favorability of the ratings of low-frequency stimuli but enhanced the ratings of high-frequency stimuli.The experiments reported here were conducted at the Laboratorium voor Experimentele Sociale Psychologie at Leuven. This article is based on the author's doctoral dissertation, which was supervised by J. M. Nuttin, Jr. I would also like to thank J. M. Nuttin, Jr., E. Van Avermaet, and J. Hatcher for their helpful comments on a previous draft.     

Word frequency and age of acquisition as determiners of picture-naming latency

In multiple-regression analysis of picture-naming latencies from an experiment modelled on Oldfield and Wingfield's (1965), with 94 stimuli and 37 adult subjects, two word frequency measures had insignificant beta weights, while two measures estimating age at which the word was learned had highly significant weights. Objects whose names were learned early were named faster. This result may have important implications for the interpretation of studies using word frequency as a critical variable. It is suggested that word retrieval may be a one-stage process that depends upon the age at which a word was learned.     

Imagery, concreteness, and meaningfulness as determiners of the emotionality of words when meaning is controlled.

We studied variables that influenced rated emotionality value of words and the contribution of each one. 218 subjects rated each word in a list of 98 pairs of words (196 words), one concrete word and one abstract word in each pair, on imagery, concreteness, meaningfulness, and emotionality. Date of entry of each word into Spanish and word length were also examined. Stepwise multiple regression procedures were performed to evaluate the contribution made by each variable to over-all emotionality values. 39.06% of the emotionality variance was explained by imagery. Concreteness and meaningfulness values contributed 3.62% and 2.82%, respectively. Word length and date of entry were rejected in the final equation, as their contributions were minimal.     

Delay or rate of food delivery as determiners of response rate

Pigeons were confronted with two keys: a green food key and a white changeover key. Food became available for a peck to the green key after variable intervals of time (mean = 113 seconds). A single peck on the changeover key changed the color of the food key to red for a fixed period of time during which the timing of the variable-interval schedule in green was suspended and the switching option eliminated and after which the conditions associated with green were reinstated. In Experiment 1 a single food presentation was obtainable during each red-key period after a minimum delay timed from the switch. This delay and the duration of the red-key period were held constant during a condition but varied between conditions (delay = 2.5, 7.5, 15, or 30 seconds; red-period duration = 30, 60, 120, 240, or 480 seconds). In Experiment 2 additional food presentations were scheduled during a 240-second red-key period with the delay to the first food delivery held constant at 30 seconds, and the delays to later food deliveries varied over conditions. Considering the data from both experiments, the rate of switching to red was a decreasing function of the delay to the first food, the delay to the second food, and perhaps the delay to the third food after a switch. There was no clear evidence that the rate of food in the red-key period made an independent contribution. The ordering of response rates among conditions was consistent with the view that each food presentation after a response adds an incremental effect to the rate of the response and that each food presentation's contribution is a decreasing function of its delay timed from the response.     

Some determiners of attention

Three experiments, using a total of 13 pigeons, examined the stimulus control acquired by the separate components of a compound visual stimulus transilluminating the pecking key. Experiment I measured the control acquired by components of compound discriminative stimuli used in discrimination training. Experiment II sought to demonstrate the effect of pretraining a single stimulus discrimination on control acquired by each component in a compound stimulus discrimination. It also investigated the effect of training the compound stimulus discrimination before the single stimulus discrimination. Experiment III sought a continuous stimulus control function when pretraining stimulus intensities were varied. The results suggest that the extent to which a bird "pays attention" to a stimulus, defined in terms of the degree of stimulus control acquired by that stimulus, is determined by how well it previously learned to discriminate that stimulus from other stimuli.     

Apparent distance vs. apparent size as determiners of figural after-effects

Abstract.— Sutherland's (1954) much discussed experimental design was analysed in a new fashion. When the original experiment was repeated as such, the expected FAE was found. However, when the same IFs and TFs were presented in a vertical position, no significant FAEs were found. The results lend support to the interpretation presented earlier by Kolehmainen (1968): The FAE found by Sutherland was apparently due to an uncontrolled binocular disparity resulting in a different localization of stimulus figures in respect to the fixation point.     

French‐learning toddlers use gender information on determiners during word recognition

In gender‐marking languages, the gender of the noun determines the form of the preceding article. In this study, we examined whether French‐learning toddlers use gender‐marking information on determiners to recognize words. In a split‐screen preferential looking experiment, 25‐month‐olds were presented with picture pairs that referred to nouns with either the same or different genders. The target word in the auditory instruction was preceded either by the correct or incorrect gender‐marked definite article. Toddlers’ looking times to target shortly after article onset demonstrated that target words were processed most efficiently in different‐gender grammatical trials. While target processing in same‐gender grammatical trials recovered in the subsequent time window, ungrammatical articles continued to affect processing efficiency until much later in the trial. These results indicate that by 25 months of age, French‐learning toddlers use gender information on determiners when comprehending subsequent nouns.