How do genetic factors and environmental factors both influence animal behavior?

The traditional view that animal behavior is either "innate" (genetically determined) or "acquired" (learned through environmental experience) is considered overly simplistic by modern researchers. Instead, all behavior is understood as the result of a complex, continuous interaction between an animal's genetic composition and the environment in which those genes are expressed.123

Genetic Influence

Genes provide the foundational "rules" or predispositions that steer an animal's development. For example, in herring gulls, chicks possess an innate tendency to peck at a red spot on their parent's bill, a behavior ethologists call a fixed action pattern. Genetic factors also influence individual differences in traits like aggression, which can be studied through selective breeding or by examining specific chromosomal regions.1243

Environmental Influence

Environmental factors—ranging from prenatal conditions in the uterus to postnatal social interactions—profoundly shape how these genetic predispositions manifest. For instance, mouse pups handled roughly by their mothers may become more aggressive as adults, regardless of their genetic strain. Furthermore, animals use learning to adjust their behavior to specific environmental circumstances, such as memorizing landmarks to locate a nest or associating specific tastes with illness.32

The Interaction

The dichotomy between nature and nurture is bridged by the concept of "instinctive learning," where genes dictate what an animal is predisposed to learn. Animals are not blank slates; they possess adaptive, specialized learning mechanisms that allow them to focus on relevant environmental information—such as a bee learning the specific color and odor of a rewarding flower—while ignoring irrelevant stimuli. Ultimately, an animal's behavior is the product of its genes setting the parameters for how it interprets and responds to its environment.213