What are Tinbergen’s four questions for studying animal behaviour?

Dutch-born British ethologist Nikolaas Tinbergen established that a comprehensive study of animal behaviour must address four distinct categories of questions, now commonly referred to as "levels of analysis." These questions are categorized into proximate and ultimate causes.12

The Four Questions

• Causation: What are the physiological and cognitive mechanisms that trigger and underlie the behaviour?2
• Ontogeny (Development): How does the behaviour develop within an individual as it matures, influenced by both genes and experience?2
• Function (Survival Value): How does the behaviour contribute to the animal's survival and reproductive success (genetic success)?12
• Evolutionary History (Phylogeny): How did the behaviour evolve from ancestral forms over evolutionary time?12

Proximate vs. Ultimate Causation

Tinbergen’s framework distinguishes between two types of explanations. Proximate causes (causation and ontogeny) explain the immediate mechanisms that allow a behaviour to occur. Ultimate causes (function and evolutionary history) explain the evolutionary origins and the selective processes that have shaped the behaviour's current utility. Addressing these levels separately is essential, as identifying a mechanism does not explain its evolutionary origin or its current survival value.12