Emergence of Leadership within a Homogeneous Group

All the authors thank Byron Crouch for his work on performing exploratory simulations of the model. Some of the computing for this project was performed at the OU Supercomputing Center for Education & Research (OSCER) at the University of Oklahoma.Large scale coordination without dominant, consistent leadership is frequent in nature. How individuals emerge from within the group as leaders, however transitory this position may be, has become an increasingly common question asked. This question is further complicated by the fact that in many of these aggregations, differences between individuals are minor and the group is largely considered to be homogeneous. In the simulations presented here, we investigate the emergence of leadership in the extreme situation in which all individuals are initially identical. Using a mathematical model developed using observations of natural systems, we show that the addition of a simple concept of leadership tendencies which is inspired by observations of natural systems and is affected by experience can produce distinct leaders and followers using a nonlinear feedback loop. Most importantly, our results show that small differences in experience can promote the rapid emergence of stable roles for leaders and followers. Our findings have implications for our understanding of adaptive behaviors in initially homogeneous groups, the role experience can play in shaping leadership tendencies, and the use of self-assessment in adapting behavior and, ultimately, self-role-assignment.Yeshttp://www.plosone.org/static/editorial#pee

Using priorities to simplify behavior coordination

ABSTRACT Previous research has used behavior hierarchies to address the problem of coordinating large numbers of behaviors. However, behavior hierarchies scale poorly since they require the state information of low-level behaviors. Abstracting this state information into priorities has recently been introduced to resolve this problem. In this work, we evaluate both the quality of priority-based behavior hierarchies and their ease of development. This is done by using grammatical evolution to learn how to coordinate low-level behaviors to accomplish a task. We show that not only do prioritybased behavior hierarchies perform just as well as standard hierarchies but that they promote faster learning of solutions that are better suited as components in larger hierarchies

The mean leadership success in initiating collective movements is shown for all treatments.

<p>All individuals within the group were given the same initial LT value, but individuals adapted their LT value based on experience in initiating collective movements attempts (mean/SE, but is small and may not be visible).</p

Two representative LT value histories depicting transitions between extremes are shown.

<p>Although LT values were relatively stable after the entire group had adapted, transitions between the extremes did occur. The more common transition was <i>(a)</i> from low to high LT value (<i>N</i> = 60 and initially high LT values). However, a few rare <i>(b)</i> high to low LT value transitions were observed (<i>N</i> = 10 and initially high LT values).</p

Histories of LT value differentiation for <i>(a)</i> fast and <i>(b)</i> slow evaluations.

<p>The evaluations both used a group size of 10 and initially low LT values. In both evaluations, LT values were distributed at the extremes of the allowed range of values after differentiation, but the number of simulated movement attempts required for differentiation differed between evaluations.</p

The mean percentage of high LT value individuals at the end of an evaluation are shown (mean/SE).

<p>The mean percentage of high LT value individuals at the end of an evaluation are shown (mean/SE).</p