From where is the group? To what is the group?: Contributions of actor−partner interdependence modeling.

Abstract

Objective: My journey as the second editor of Group Dynamics: Theory and Research helped me realize two important questions that I and other group dynamics research need to address. Where is the group? And what is the group? Method: I briefly review the literature variously described as group effects, partner effects, and mutual influence to highlight the importance of examining how the group affects the individual. Next, I review the literature, which shows that calculating the mean of group members' perceptions and behaviors does not explain the entire effect of the group. Results: There is extensive evidence that the group or other group members have a strong effect on the perceptions and behaviors of individual group members. In addition, measuring dispersion and homogeneity of group members' perceptions and behavior can add to our understanding of the group effect. Conclusions: Group researchers should expand their examination of the effect of the group by including measures of dispersion and homogeneity in their research. Highlights and Implications• The actor−partner interdependence model is an important method for understanding the effect of the group.• Other group members' perceptions and behaviors have a larger effect on the individual group member than their own perceptions and behaviors.

Twenty-five years of Group Dynamics: Theory, research and practice: Introduction to the special issue.

“…The second editor of Group Dynamics was Dennis Kivlighan from 2002 to 2007. In his contribution to this special issue, Kivlighan (2021) focuses on the fundamental question of what is a group? He does so from the perspective of data analysis by specifically examining actor-partner interdependence models (APIM) and variance partitioning.…”

“…In addition to APIM, Kivlighan (2021) reviews the use of variance partitioning in group research. In longitudinal group data, there are several sources of variance that can be explained (see Gullo et al, 2021, for an example).…”

“…It is Kilvlighan’s (2021) discussion of within-team variance that dovetails with Forsyth (2021) unified theory of cohesion. APIM models that look at within-team variance evaluate three partner effects: The amount (average group level), the consistency (variability in scores in a session), and the interaction of amount and consistency.…”

“…Highlights and ImplicationsTo celebrate the 25th anniversary of Group Dynamics: Theory, Research, and Practice the previous and current editors of the journal each review a key topic in group dynamics research and provide a roadmap for the next 25 years of research in these topics.Donelson Forsyth (2021) presents a unified theory of cohesion, an important concept for both group psychology and group psychotherapy. Forsyth argues that a clear and definitive view of cohesion is necessary to move the research forward and he presents a new psychometric scale.Dennis Kivlighan (2021) discusses use of actor-partner interdependence models (APIM) and multilevel modeling of grouped data. He points to the need for such data modeling techniques for group researchers to truly estimate complex phenomena that occur in groups.Craig Parks (2021) tackles the larger social consequences of cooperation and lack thereof.…”

“…Dennis Kivlighan (2021) discusses use of actor-partner interdependence models (APIM) and multilevel modeling of grouped data. He points to the need for such data modeling techniques for group researchers to truly estimate complex phenomena that occur in groups.…”