Transactive memory is a psychological hypothesis first proposed by Daniel Wegner in 1985 as a response to earlier theories of "group mind" such as groupthink.Wegner, D. M., Giuliano, T., & Hertel, P. (1985). Cognitive interdependence in close relationships. In W. J. Ickes (Ed.), Compatible and incompatible relationships (pp. 253–276). New York: Springer-Verlag. A transactive memory system is a mechanism through which groups collectively encode, store, and retrieve knowledge. Transactive memory was initially studied in couples and families where individuals had close relationships but was later extended to teams, larger groups, and organizations to explain how they develop a "group mind", a memory system that is more complex and potentially more effective than that of any of its individual constituents. A transactive memory system includes memory stored in each individual, the interactions between memory within the individuals, as well as the processes that update this memory. Transactive memory, then, is the shared store of knowledge.
According to Wegner, a transactive memory system consists of the knowledge stored in each individual's memory combined with metamemory containing information regarding the different teammate's domains of expertise. The transactive memory system works similarly to external memory, where other members of the group are the external memory aid. Just as an individual's metamemory allows them to be aware of what information is available for retrieval, so does the transactive memory system provide teammates with information regarding the knowledge they have access to within the group.Wegner, D. M. (1986). Transactive memory: A contemporary analysis of the group mind. In B.Mullen & G. R. Goethals (Eds.), Theories of group behavior (pp. 185–205). New York: Springer-Verlag Group members learn who knowledge experts are and how to access expertise through communicative processes. In this way, a transactive memory system can provide the group members with more and better knowledge than any individual could access on their own.
History Transactive memory was first envisioned by Daniel Wegner in 1985. This concept proposed that when two individuals spend a lot of time around each other and work together, they create a shared store of knowledge between the members. In essence, one member of the couple could store information within their partner and then recall that information by asking their partner about it. This concept was different and unique from other descriptions of socially distributed cognition in that it describes a situation where individuals hold different knowledge compared to shared information, and members of the group engage in transactions to assist in recall of the stored information. In a recent review, Ren and Argote described transactive memory as existing of both a structural component (the linkages of individual memory to the collective) and transactive processes that make the transactive memory dynamic. Wegner first proposed these three processes which occur in groups that lead to the formation and reification of transactive memory: encoding, storage, and retrieval described more below. In a series of experiments, Hollingshead found that romantic partners (who are assumed to have transactive memory) performed better on knowledge recall than dyads and that couples will memorize more words in a list than two strangers when they are rewarded on number of unique words you recall. The explanation for these findings are that couples know how best to remind each other of the knowledge they have, and that couples have a good conception of the other's knowledge and will therefore avoid memorizing words within their partner's domain. Strangers don't have access to this same shared information which leads to poorer performance in these kinds of tasks. Transactive memory was further extended by Diane Liang and colleagues into the realm of work groups. In this work, the development of transactive memory was conceived of as a way to improve group's performance when engaging in interdependent tasks. After this extension, transactive memory became more prolific in organizational behavior among other disciplines.
Transactive processes Just like human memory, the development of a transactive memory system involves three stages: encoding, storage and retrieval. These processes are transactive, meaning that they are updated as members exchange information with one another.
Encoding
In the encoding stage, the teammates gain information on the other team members' domains of knowledge and categorize it by ascribing each knowledge domain to the corresponding team member. Sometimes, this acquaintance can emerge through "who did what" or "who knows what" conversation, or even through direct instruction such as by telling a teammate to remember certain information. There may also be discussion and negotiation of where and in what form to store information in the group.
The encoding process is very important in the development of transactive memory. Encoding occurs through interaction between teammates: through sharing knowledge and seeking information from other team members, teammates learn the expertise of each team member as a first essential step towards specialization. These experts then are responsible for continuing to encode new and relevant information in their domains of knowledge.
Storage In the storage stage, the relevant information is stored in the possession of the team member, or members, with the corresponding expertise; once the experts have been identified, new information is transmitted directly to those team members. This improves the learning process and reduces the load on the memory of individual teammates. With transactive memory storage, a team member only has to remember the information in their domain of expertise, while they only have to remember what the other members' domains of expertise are rather than storing all the information in the transactive memory.
Information may be also lost or modified during storage for transitive memory, as is the case in individual memory. These modifications, however, may be even more rapid and impactful than in individual memory because the information is scattered and stored with multiple members in the group, making the information more readily replaced with misinformation.
Retrieval During the retrieval stage, a group member uses the developed transactive memory to identify a group member that specializes in the required knowledge area and then turns to that member to attain the knowledge. If the inquiring member has not encoded in their individual metamemory who specializes in the knowledge, retrieval can be initiated by asking other members in the storage system for who the expert who specializes in the information they want to retrieve is, then connecting with that expert after a series of consultations. If this information is accurate and useful, the linkage to the member with specialized knowledge is strengthened. If the information is not accurate, then the encoding stage is entered into again such that information about the inaccuracy of the knowledge the specialized member provided is re-encoded and stored in the transactive memory system.
Development Much research has shown that a transactive memory system is primarily developed through interactions between team members. Training on the task that a group is expected to do together has been shown to assist in the development of a transactive memory system. In this study, when the group members were trained together, the team developed a stronger transactive memory system, recalled more information about the process, and made fewer errors compared to teams where individuals had gone through the same training but separately. The researchers concluded that the interactions that took place during the joint training allowed the team members to develop an understanding of their teammates' skills, assisted their search for relevant information about the task from their teammates, and assess the accuracy and reliability of this information. As a result, groups that trained together performed better in the task. In a later study, these same researchers also determined that familiarity with their teammates or liking didn't explain the differences between groups that were trained together and those that were not. In this study, the researchers gave the groups that didn't train together a team building exercise but they still did not do as well as the trained together group.
Furthermore, research has shown that the knowledge about who knows what can be available before the team processes. At the first stage in a group's life cycle, knowing each of the team members' expertise allows the group to distribute work in a more efficient way and allocate different assignments to team members that are the most qualified for these assignments. The existence of many interactions in the early stages of group formation provides each of the teammates the opportunity to get to know other team members' training, level of expertise or the lack of knowledge in certain areas, and develop a shared understanding of the task's requirements and the way that the total of the teammates knowledge combines.
Hence, it seems that communication serves as a crucial component in the development of transactive memory. Yet, it seems that not any kind of communication and interaction between team members will bring to the construction of transactive memory. Communication, in general serves as a way of transferring information from one person to another, but for the purpose of transactive memory construction this communication must deal with information regarding the knowledge, expertise and relevant experience of other individuals in the system. If the team members communicate more face to face while planning a project the TMS will emerge faster and will be stronger. The level of face to face communication while the team is planning could predict implementation-phase TMS.
Moreland & Myaskovsky (2000) showed that transactive memory can be developed without any interaction between teammates. As a substitute to teammates' communication they provided group members feedback ranking team members' skills in the relevant task domains before they started performing the task. Although the feedback and the information regarding teammates knowledge was provided by the researchers and teammates did not communicate with each other beforehand, this information positively affected the team's transactive memory score and performance.Moreland R.L and Myaskovsky L. (2000). Exploring the Performance Benefits of Group Training: Transactive Memory or Improved Communication? Organizational Behavior and Human Decision Processes Vol. 82, No. 1, 117–133. This experiment demonstrated that the sharing specific information regarding team members' knowledge and domains of expertise formation is necessary for transactive memory development, either through direct interaction or by another means of information transformation.
Indicators Many researchers consider the basic components of transactive memory system to be specialization, coordination and credibility. This is a common misconception of how transactive memory systems operate within groups. These indicators of TMS occur after a group has established a transactive memory system and are due to the existence of transactive memory within the group. Because these three factors occur more prevalently in groups that have developed a TMS, they are often measured as a proxy for measuring the exact transactive memory system. The most prevalent measure of transactive memory as developed by Kyle Lewis measures these three components as indicators that a group has developed a transactive memory. Other measures, namely Austin's attempts to measure the perceptions of expertise within the group as a more direct measure of transactive memory.