Social Feedback and the Emergence of Leaders and Followers

Abstract

In many animal groups, certain individuals consistently appear at the forefront of coordinated movements [1-4]. How such leaders emerge is poorly understood [5, 6]. Here, we show that in pairs of sticklebacks, Gasterosteus aculeatus, leadership arises from individual differences in the way that fish respond to their partner's movements. Having first established that individuals differed in their propensity to leave cover in order to look for food, we randomly paired fish of varying boldness, and we used a Markov Chain model to infer the individual rules underlying their joint behavior. Both fish in a pair responded to each other's movements-each was more likely to leave cover if the other was already out and to return if the other had already returned. However, we found that bolder individuals displayed greater initiative and were less responsive to their partners, whereas shyer individuals displayed less initiative but followed their partners more faithfully; they also, as followers, elicited greater leadership tendencies in their bold partners. We conclude that leadership in this case is reinforced by positive social feedback.

Pre- and post-natal stress have opposing effects on social information use

“…As natural conditions present a wide range of different stressors at various developmental stages, these factors may help explain why certain social foragers choose to scrounge from others' findings [10], and why specific individuals tend to lead groups while others follow [11]. rsbl.royalsocietypublishing.org Biol Lett 9: 20121088 …”

“…This study is the first to test a prominent but rarely addressed social learning theory in a developmental framework. As evidence for developmental conditions shaping adult phenotypes is accumulating [9], addressing this question might help explain consistent individual differences in social foraging tactics [10] and leadership [11].…”

The role of individuality in collective group movement

“…This in turn allows groups to maintain their coherence and enables group members to realize the benefits of group living [7]. To date, however, most studies of collective behaviour have assumed that group members are identical in their movements and responses to their neighbours [2][3][4] (but see [8][9][10] for theoretical predictions and [11,12] for empirical observations about individual differences in groups). This common assumption of homogeneity contrasts with a large and growing body of work documenting consistent inter-individual differences in behaviour [13][14][15][16][17][18] and evidence that differences in the social affiliations between group members, and individual differences, can affect leadership and the collective decision-making process [12,19,20].…”

Social dynamics, network structure, and information diffusion in fish shoals.

“…Bolder individuals tend to exhibit decreased social attraction towards group mates, as well as less temporally stable associations (Harcourt et al, 2009;Kurvers et al, 2012;Aplin et al, 2013). As a result, fragmentation can occur within groups composed predominately of bolder individuals (Dyer et al, 2009;Michelena et al, 2009).…”

“…The willingness of an individual to accept greater risks in return for potentially greater rewards, i.e., boldness, is a well-studied facet of personality (Réale et al, 2007) that may reflect a general trade-off between life history strategies optimized for productivity versus those prioritizing survival (Smith & Blumstein, 2008). As a result of its influence across a range of behavioral contexts, an individual's position on the bold-shy axis frequently shapes the nature and outcomes of its social interactions (Harcourt et al, 2009;Kurvers et al, 2010;Aplin et al, 2013). Within-group variation in personality can also impact the fitness of group members and influence group-level outcomes (Farine, Montiglio, et al, 2015).…”