Article
Leader–Follower Role Allocation for Physical Collaboration in
Human Dyads
Rebeka Kropiv šek Leskovar
1,
*
,†
, Jernej
ˇ
Camernik
2,†
and Tadej Petriˇc
1,†
Citation: Kropivšek Leskovar, R.;
ˇ
Camernik, J.; Petriˇc, T. Leader–
Follower Role Allocation for Physical
Collaboration in Human Dyads. Appl.
Sci. 2021, 11, 8928. https://doi.org/
10.3390/app11198928
Academic Editor: Dario Richiedei
Received: 1 September 2021
Accepted: 21 September 2021
Published: 25 September 2021
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4.0/).
1
Jožef Stefan International Postgraduate School, 1000 Ljubljana, Slovenia; tadej.petric@ijs.si
2
Applied Cognitive Psychology, Faculty for Computer Science, Engineering, and Psychology, Ulm University,
89081 Ulm, Germany; jernej.camernik@uni-ulm.de
* Correspondence: rebeka.leskovar@ijs.si
† Current address: Department for Automation, Biocybernetics and Robotics, Jožef Stefan Institute,
Jamova ulica 39, 1000 Ljubljana, Slovenia.
Featured Application: Findings presented in this study can be seen as beneficial in better un-
derstanding the collaborative dynamics that present themselves in human collaboration as well
as in the further development of novel robot control models. Implementing the leader–follower
role allocation studied in this paper into a robot control model allows the robot partner to assume
both the role of a follower and that of a leader when necessary. This can be especially useful in
social robotics for effective physical rehabilitation. In this regard the results could in the future
be incorporated in the design of a human–robot collaborative system that is able to support the
human user in more effective skill learning by adjusting its influence on the task performance.
Abstract:
People often find themselves in situations where collaboration with others is necessary to
accomplish a particular task. In such cases, a leader–follower relationship is established to coordinate
a plan to achieve a common goal. This is usually accomplished through verbal communication.
However, what happens when verbal communication is not possible? In this study, we observe the
dynamics of a leader–follower relationship in human dyads during collaborative tasks where there is
no verbal communication between partners. Using two robotic arms, we designed a collaborative
experimental task in which subjects perform the task individually or coupled together through a
virtual model. The results show that human partners fall into the leader–follower dynamics even
when they cannot communicate verbally. We demonstrate this in two steps. First, we study how
each subject in a collaboration influences task performance, and second, we evaluate whether both
partners influence it equally or not using our proposed sorting method to objectively identify a
leader. We also study the leader–follower dynamics by analysing the task performance of partners
during their individual sessions to predict the role distribution in a dyad. Based on the results of our
prediction method, we conclude that the higher-performing individual performance will assume the
role of a leader in collaboration.
Keywords:
human collaboration; leader–follower dynamics; role allocation; dyadic interaction;
human–robot interaction
1. Introduction
In our day-to-day lives, we often find ourselves in situations where collaborating with
other people is necessary to achieve a certain task. A social behaviour that innately occurs
in group collaboration is the leader–follower dynamic, where in order to perform a collabo-
rative task effectively, one of the partners in collaboration must assume the role of a leader
whether coordination is done through verbal [
1
] or non-verbal communication—through
physical interaction. This dynamic has been thoroughly researched from a psychological
and sociological perspective as seen in [2,3], however has yet to be addressed in the same
amount from a physical or kinematic standpoint. Sebanz et al. [
4
] reviewed aspects of
Appl. Sci. 2021, 11, 8928. https://doi.org/10.3390/app11198928 https://www.mdpi.com/journal/applsci
