Fear is considered an integral part of the brain's defensive mechanism that evolved to protect animals and humans from predation and other ecological threats. Hence, it is logical to study fear from the perspective of antipredator-survival behaviors and circuits by sampling a range of threatening situations that organisms are likely to encounter in the wild. In the past several decades, however, mainstream fear research has focused on the importance of associative learning; that is, how animals become frightened of innocuous cues as consequences of their contingent pairing with aversive events. While significant discoveries have been made, contemporary fear models derived from learning studies are likely to provide only a partial picture of the brain's fear system because they cannot simulate the dynamic range of risky situations in nature that require various adaptive actions and decisions. This review considers two different approaches to study fear, grounded on behaviorism and ethology and examines their contributions in revealing the naturalistic workings of fear in guiding and shaping behavior as animals make real-world choices.

恐惧被认为是大脑防御机制的一个组成部分，该机制的进化是为了保护动物和人类免受捕食和其他生态威胁。因此，通过对生物体在野外可能遇到的一系列威胁情况进行采样，从反捕食者生存行为和回路的角度来研究恐惧是合乎逻辑的。然而，在过去的几十年里，主流的恐惧研究集中在联想学习的重要性上。也就是说，动物如何因为与厌恶事件的偶然配对而变得害怕无害的暗示。虽然已经取得了重大发现，但源自学习研究的当代恐惧模型可能只能提供大脑恐惧系统的部分图像，因为它们无法模拟自然界中需要各种适应性行动和决策的危险情况的动态范围。这篇综述考虑了基于行为主义和动物行为学的两种不同的恐惧研究方法，并探讨了它们在揭示恐惧在动物做出现实世界选择时引导和塑造行为的自然主义作用方面的贡献。