A new study led by the Konrad Lorenz Research Center for Behavior and Cognition at the University of Vienna sheds light on a long-standing mystery in animal behavior: why do certain individuals gain more influence than others within a group? The research shows that bold geese – but not aggressive ones – are more likely to be accepted as leaders, while exploratory individuals tend to follow them – revealing a nuanced interplay of personality and social roles in collective movement decisions. The results of the study have just been published in the journal iScience.
While simple interaction rules can explain how animal groups move together, we still know little about the long-term consistency of social roles in the wild – and why certain animals succeed in exerting more influence over collective decisions than others. To better understand these dynamics, the new study investigated whether individual greylag geese (Anser anser) show stable tendencies to lead or follow, and whether these behavioral patterns can be predicted by traits such as boldness, aggressiveness, and exploration. The researchers observed a marked flock at the Konrad Lorenz Research Station in Grünau im Almtal, Austria – a population originally introduced by Nobel laureate Konrad Lorenz in the 1970s. Over a period of four years, they documented hundreds of collective departures, noting who initiated flight, who responded, and how large the departing parties were. In parallel, they assessed personality through standardized tests: flight initiation distance for boldness, mirror response for aggressiveness, and novel-object interaction for curiosity. The goal was to understand how individual variation shapes movement decisions and the flow of information through the flock.
Bold leaders and curious followers
The study offers two key insights: individual geese exhibit stable personality traits – boldness, aggressiveness, and exploration – that persist over years, and they move daily in collective subgroups to forage and roost across various valley locations. Results show that bolder individuals are more likely to be followed when they give a departure call and take flight. Those who follow tend to be exploratory, preferring bold over aggressive or dominant leaders.
Each day, the flock faces a tradeoff when moving to new foraging grounds or sleeping sites: balancing the safety of familiar, secure locations with the potential benefits of exploring unknown areas. Geese with bold personalities help manage this tradeoff by offering protection during risky movements, while curious individuals promote discovery and spread innovation.
Contrary to expectations, aggressiveness did not predict leadership during group departures, even though more aggressive geese often occupy higher social ranks. The most influential initiators were bold but not aggressive – a pattern that suggests a protective rather than dominant leadership style. These bold individuals offer safety in uncertain situations, while exploratory followers contribute by identifying new opportunities and transmitting information through social learning.
Rethinking influence and Leadership
"This research helps to explain why individuals with specific traits consistently wield more influence," says lead author Sonia Kleindorfer. “More importantly, it draws attention to followers – often overlooked in our human fascination with securing resources. What if followers actively choose whom to follow based on the benefits they receive? This shifts focus to the cognitive abilities of followers and challenges traditional ideas about which traits matter most in leaders.”
By shifting attention away from aggressive, dominant individuals – who may maintain control through fear – toward the social and cognitive strategies of followers, this study opens new pathways for understanding collective decision-making, social learning, and cultural evolution – not only in geese but across many species, including humans.
See more information about the geese on Youtube.
Original publication:
Personality predicts collective behavior in greylag geese: influencers are bold and followers are exploratory. Sonia Kleindorfer, Andrew C. Katsis, Didone Frigerio, Jonas Lesigang, Dina Mostafa, Lauren K. Common. In iScience.
