Related Experiment Video
Updated: May 13, 2026
08:43
Boldness, Aggression, and Shoaling Assays for Zebrafish Behavioral Syndromes
Published on: August 29, 2016
Could relatedness help explain why individuals lead in bottlenose dolphin groups?
Jennifer S Lewis1, Douglas Wartzok, Michael Heithaus
1Florida International University, Department of Biological Sciences, Miami, Florida, USA. jennifer.lewis1@fiu.edu
Plos One
|March 22, 2013
Summary
Bottlenose dolphin leaders may benefit by guiding relatives, gaining indirect fitness advantages. This study reveals higher relatedness in leader-follower pairs, suggesting kin selection drives leadership in these social mammals.
Area of Science:
- Behavioral Ecology
- Marine Mammal Science
- Evolutionary Biology
Background:
- Group leadership is common, but leader benefits are often unclear, especially in species with shared resource discovery.
- In complex environments, leaders might gain indirect benefits by aiding relatives, a concept explored in bottlenose dolphins.
Purpose of the Study:
- To investigate if leadership in bottlenose dolphins provides indirect benefits to leaders through kin selection.
- To compare relatedness between leader-follower pairs and non-leader pairs in a dolphin population.
Main Methods:
- Analysis of genetic relatedness between identified leader-follower pairs.
- Comparison of relatedness in leader-follower pairs versus control pairs (associating individuals without leadership roles).
- Correlation analysis between relatedness and association indices for both pair types.
Main Results:
- Leader-follower pairs exhibited significantly higher average relatedness than expected by chance.
- No elevated relatedness was observed in non-leader-follower pairs.
- Relatedness positively correlated with association in leader-follower pairs, but not in non-leader pairs.
Conclusions:
- Findings suggest bottlenose dolphin leaders may gain indirect fitness benefits by leading relatives.
- Kin selection provides a plausible explanation for leadership maintenance in this fission-fusion dolphin society.
- This research offers a mechanism for leadership in social species where direct benefits are minimal.
Related Concept Videos
00:57Inclusive Fitness
Most altruistic behavior—in which one animal helps another at a cost to themselves—occurs between relatives. Scientists think these altruistic behaviors evolved because they increase the inclusive fitness of the animal providing help.
01:54Convergent Evolution
Evolution shapes the features of organisms over time, ensuring that they are suited for the environments in which they live. Sometimes, selection pressure leads to the rise of similar but unrelated adaptations in organisms with no recent common ancestors, a process known as convergent evolution.
01:37Social Loafing
Another way in which a group presence can affect performance is social loafing—the exertion of less effort by a person working together with a group. Social loafing occurs when our individual performance cannot be evaluated separately from the group. Thus, group performance declines on easy tasks (Karau & Williams, 1993). Essentially individual group members loaf and let other group members pick up the slack. Because each individual’s efforts cannot be evaluated, individuals become less...
02:12Relationship Formation
What do you think is the single most influential factor in determining with whom you become friends and whom you form romantic relationships? You might be surprised to learn that the answer is simple: the people with whom you have the most contact. This most important factor is proximity. You are more likely to be friends with people you have regular contact with. For example, there are decades of research that shows that you are more likely to become friends with people who live in your dorm,...
04:49Robbers Cave
During the 1950s, the landmark Robbers Cave experiment demonstrated that when groups must compete with one another, intergroup conflict, hostility, and even violence may result. At the Oklahoman summer camp, two troops of boys—termed the Rattlers and the Eagles—took part in a week-long tournament. During this time, their negativity culminated in derogatory name-calling, fistfights, and even vandalism and destruction of property. However, this work also revealed that such tension could be...
01:31In- and Out-Groups
People all belong to a gender, race, age, and social economic group. These groups provide a powerful source of our identity and self-esteem (Tajfel & Turner, 1979) and serve as our in-groups. An in-group is a group that we identify with or see ourselves as belonging to.