What characterizes altruistic behavior in animals?

Altruistic behavior in animals is characterized by actions that benefit other individuals, often at a cost to the individual's own fitness, and without any expectation of reciprocation. This means that an animal exhibiting altruistic behavior will assist another, such as by grooming, sharing food, or providing protection, purely for the benefit of that other individual, rather than for immediate personal gain or future reciprocation.

This behavior can enhance group survival and well-being, though it may reduce the individual’s personal reproductive success. Such acts are often observed in social animals, where individuals may sacrifice their own safety or resources for the benefit of their group or kin, promoting the overall fitness of their species or community. This principle aligns with the concepts of kin selection and inclusive fitness, where the genetic legacy is supported by helping relatives.

The other options provided do not capture the essence of altruism accurately. For instance, altruism is not limited to helping only unrelated individuals, nor is it primarily associated with increasing predation risks or being self-serving. Altruistic acts may paradoxically enhance the survival of related individuals, sometimes leading to indirect benefits for the altruist through shared genes.