The question of which animal is the kindest is complex because “kindness” is a human moral concept that implies intentionality and awareness. Scientists instead explore observable actions that align with this idea, focusing on behaviors that benefit another individual at a cost to the actor. This exploration reveals that traits resembling kindness, such as cooperation and helping, are widespread across the animal kingdom. These behaviors are evolved strategies that offer a survival advantage in social environments.
How Scientists Define Kindness in Animals
Scientists use specific terms to analyze helping behavior in the natural world, moving beyond the human idea of kindness. The primary term is “altruism,” which describes a behavior that increases the fitness of a recipient while decreasing the fitness of the individual performing the action. Fitness is measured by reproductive success, or the number of offspring an animal is likely to produce.
Another important concept is “empathy,” defined as the ability to share and understand the feelings of another. Since it is impossible to definitively measure an animal’s internal motivations, researchers focus on observable actions that suggest an understanding of another’s state. These objective definitions allow for the study of self-sacrificing behavior across many different species.
Examples of Helping Within a Species
Many highly social species display complex behaviors that involve assistance and protection among group members. These actions often come at a cost to the helper, showcasing a form of biological altruism.
Vampire bats, for instance, cannot survive more than approximately 60 hours without a blood meal. A successful forager will regurgitate a portion of its collected blood to share with a roostmate who has failed to feed that night. This act is costly, as the donor moves closer to its own starvation point, yet it is a common occurrence in their colonies.
Dolphins and whales are frequently observed assisting their injured or sick companions. When a member of the pod is too weak to reach the surface to breathe, other dolphins will support the individual, using their bodies to push the distressed animal toward the air. These support-swimming behaviors can last for hours, requiring sustained effort from the helpers.
African elephants demonstrate profound care, particularly around death and distress. When a herd member is injured, others often gather around, attempting to lift the individual or spraying water on them. Elephants have also been documented covering the bodies of dead members, even those of unrelated elephants or other species, with branches and dirt.
The Phenomenon of Interspecies Care
Perhaps the most compelling examples of apparent kindness are those involving animals helping members of an entirely different species. These instances, while sometimes anecdotal, suggest that the impulse to nurture or protect can extend beyond species lines.
One widely documented example involves a young humpback whale that protected a seal from an attack by killer whales. The humpback positioned its massive body between the seal and the predators, lifting the seal onto its chest to keep it safe. The whale continued to shield the seal until the threat had passed, risking itself for a non-related animal of a different species.
In captive settings, a famous instance involves Koko the gorilla, who adopted and cared for kittens as if they were her own offspring. She exhibited maternal behaviors, gently petting and nurturing the small animals. Another example includes a baboon who “adopted” a young bush baby, carrying and grooming the infant in its troop.
In the wild, there are instances of mutually beneficial interactions that verge on cooperation, such as the relationship between coyotes and American badgers. These two predators will sometimes hunt together, with the badger flushing burrowing rodents out of their dens where the coyote can catch them. This cooperative hunting increases the success rate for both animals, showing a surprising alliance between two species that would normally compete.
Why Animals Help Others
The evolutionary persistence of altruistic behavior, despite its immediate cost to the individual, is explained by two primary mechanisms. These mechanisms demonstrate that helping behavior is driven by genetic self-interest, albeit an indirect one.
The first is known as kin selection. This theory explains that an animal’s long-term genetic success is based on the survival of its relatives. By helping a sibling, cousin, or offspring survive, the altruistic individual ensures that a portion of their shared genes is passed on. For the trait to evolve, the benefit to the relative, multiplied by the degree of relatedness, must outweigh the cost to the helper.
The second mechanism is reciprocal altruism, which explains helping behavior between non-relatives. This strategy is based on the expectation that the favor will be returned in the future, often summarized as “if you scratch my back, I’ll scratch yours.” For this to work, animals must live in stable social groups, be able to recognize individuals, and remember past interactions. The blood-sharing in vampire bats is a prime example of reciprocal altruism in action.