Collaborative Inhibition 1 Running head : COLLABORATIVE INHIBITION Collaborative inhibition : A counterintuitive phenomenon

Recollection is frequently social; people tend to remember with others and when they do, their joint recollection is enhanced (Meudell, Hitch & Kirby, 1992). While one intuitively thinks that collaboration would enhance memory, Weldon, et al. (1997) argued that recalling with others impairs retrieval of "unique items. " This collaborative inhibition (CI), occurs when pairs of subjects recall fewer correct "unique" items than others recall in isolation. This is a common result in many studies and has been attributed to both social and cognitive causes. This study examined whether or not collaborative inhibition would disappear if the total possible number of unique items were equal in groups and individuals randomly put into pairs and triads. In a series of experiments, we showed that the nominal grouping condition remembered more unique correct items than collaborative groups, but the effects of collaborative inhibition disappeared when the collaborative subjects were given an equal number of chances to remember as the isolated subjects. This provides evidence that the effects of collaborative inhibition are caused by an artifact in the scoring procedure and not a memory failure. This finding is vital in memory research because it alleviates the doubt on group recall caused by collaborative inhibition. Collaborative Inhibition 3 Collaborative inhibition: A counterintuitive phenomenon Most memory research conducted analyzes individual participants' data. The few past studies that investigated the relationship between individual recall and recall in a group all concluded that groups remember more items accurately than an individual (Meudell et aI., 1992). Thus the expression "Two heads are better than one," became a common belief. With memory, particularly episodic memory, relying heavily on interpersonal interactions through the reminiscing of shared experiences, that conclusion seemed both logical and precise. Early Collaborative Research Meudell, Hitch, and Kirby (1992) took the analysis of collaborative recall a step further by asking whether the trend of groups recalling more items was due to collaborative groups facilitating memory or simply due to the a statistical pooling of responses. The authors tested their theory by having participants recall in two separate sessions immediately after each other. In the fIrst session all participants individually completed a free-recall of words learned three months before. Immediately after the fIrst recall participants performed another recall with some put into pairs (dyads) and some left as individuals to act as a control group. Scoring the data played an important part in how the results were analyzed. Meudell et aI. (1992) theorized that if group recall facilitated individual recall then group recall would not only contain more items than individual recall, but it would also contain items that had not appeared on either of the participants' individual recall. That is, collaborative group recall would elicit new information that would not have been recalled if the individuals stayed separate. To Collaborative Inhibition 4 examine that hypothesis, participants' recall was compared as individual recall to group recall to see if new words appeared. Surprisingly, the results showed no significant difference in new items recalled in collaborative groups than in individuals in the second recall session. This led Meudell et al. to conclude two major theories on collaborative group recall; collaborative groups do not facilitate individual recall and the trend of groups having a higher mean of items recalled is most likely due to simple pooling of answers. Not only did they find that group recall showed no facilitation of new items, but they also hinted at a possible inhibitory mechanism associated with collaborative group recall. Other research comparing individual recall with collaborative recall found results that suggested an inhibitory mechanism involved in collaborative recall, although none thoroughly investigated those counterintuitive fmdings until Weldon arid Bellinger (1997). Collaborative Inhibition occurs when interacting collaborative groups fail to out perform the combined performance of individuals (Weldon & Bellinger, 1997). Nominal Groups: Optimizing Group Recall Before continuing the examination of collaborative inhibition, some explanations in terminology and methodology need to be made. First of all, the terms collaborative group and group are used interchangeable. Secondly, the method used in collaborative inhibition studies to determine the predicted performance value of a group requires some clarification. In order to compare the output of a collaborating group to that of an individual, it is necessary to compare the performance of a collaborating or interacting group to the performance of a nominal or non-interacting group (Thompson, 2008). Nominal groups Collaborative Inhibition 5 consist of at least two individuals who work alone during the entire experiment. The nominal groups are then formed during the analysis of the data by randomly placing individual participants' data together as if they had worked together collaboratively. The data are scored by pooling together unique, non-redundant, answers from each individual set of data. For example, if the nominal group consists of two participants with participant 1 recalling items a,b,c,d,e while participant 2 recalling items d,e,f,g,h,j then the combined performance would be a,b,c,d,e,f,g,hj and would be the nominal group's performance (Thompson, 2008). The scores from the nominal group act as a predictor for the performance of a collaborating group due to the findings in collaborative memory research that colhtborative group performance is just a pooling of the individuals (Meudell et al.,1992). Comparing the scores of a nominal group to a collaborating group produces three potential predictions. (1) If the collaborating group performs greater than the nominal group, then collaboration facilitates, or enhances performance. (2) If the performance ofboth the collaborating and the nominal groups are equal, then there is no effect of collaboration on performance. (3) If the collaborating groups perform less than the nominal groups, then collaboration must inhibit performance (Weldon & Bellinger, 1997). Collaborative inhibition is found when the third prediction is correct. Early Collaborative Inhibition Research Using the concept of nominal groups, Weldon and Bellinger (1997) were the first to explore collaboration in memory specifically set on determining whether groups or individuals are more productive in recall. The goal of their study was to determine whether collaboration facilitates, inhibits, or pools individual's knowledge. They set up their experiments in a similar fashion to Meudell et al. (1992), having participants recall Collaborative Inhibition 6 the same items in two testing sessions, one after the other, either individually-individually (II), collaboratively-collaboratively (CC), individually-collaboratively (lC), or collaboratively-individually (CI). For example, when working in isolation, one person might remember the items coffee, eggs, toast, jam and bacon and the other remembers coffee, eggs, jelly, juice and cereal (See Table 1). When these two people remember together after a one-week delay, they remember coffee, eggs, jelly, jam, juice and cereal. While they remember more at the one-week delay (six items instead of the five each remembered individually), the number of unique correct items recalled between the two of them is less than when they worked alone (six unique items as a pair instead of eight when working alone). The results showed that despite the output of a collaborating group being larger than an individual's output, collaborating group's pefformance did not exceed the predicted performance of the nominal group. They called this curious lack of optimization collaborative inhibition. Social Explanations ofCollaborative Inhibition With memory being a social activity, a logical reason for CI can be attributed to previously established theories of social inhibition dealing with other cognitive functions, such as brainstorming and group productivity. One such theory of is socialloafmg. As described by Latane, Williams and Harkins (1979), social loafing refers to "a decrease in individual effort due to the social presence of other persons. " Latane et al. (1979) demonstrated social loafing though two physical tasks, cheering and clapping, that are usually done in social settings. They compared the measured intensity of an individual clapping/cheering by themselves to the intensities of clapping/cheering in groups of two, Collaborative Inhibition 7 four, and six. The results showed that, although the overall intensity of the group was higher than the individuals', the group's intensity level was not just a summation ofthe individual's intensity. Instead, group intensity level never represented the predicted value of multiplying the individual intensity level by number ofpeople in the group. In fact, as the group size increased, ratio of actual intensity level to predicted intensity level decreased. That is, two-person groups only performed to 71% of their predicted performance, while six-person groups performed at 40%. These results support the social loafing because in a group, one feels as if they do not need to put as much effort into the activity because there are other people to contribute. Social loafing fits logically as the cause of collaborative inhibition because the effect of collaborative inhibition matches the effect seen in social loafing, that as a group gets larger they stray even farther away from the predicted value ofperformance because there are others to assist in the contributions to the group (Latane et. al, 1979). Weldon, Blair, and Huebsch (2000) investigated whether motivational factors, such as social loafing, contributed to CI during recall.