The ethological deconstruction of fear(s)

Abstract

The natural world presents a myriad of dangers that can threaten an organism's survival. This diversity of threats is matched by a set of universal and species specific defensive behaviors which are often subsumed under the emotions of fear and anxiety. A major issue in the field of affective science, however, is that these emotions are often conflated and scientists fail to reflect the ecological conditions that gave rise to them. I attempt to clarify these semantic issues by describing the link between ethologically defined defensive strategies and fear. This in turn, provides a clearer differentiation between fears, the contexts that evoke them and how they are organized within defensive survival circuits.

Figure 1

A simple flow model showing the links between the natural world, including the traits, spatial and temporal properties of the threat and the cognitive/behavioral strategies and computations that have evolved for successful escape and avoidance of danger. Finally, these strategies are embedded in defensive survival circuits.

Figure 2

An example of how levels of predatory imminence map onto defensive survival circuits. The left panel illustrates several of Fanselow and Lester’s levels of ‘predatory imminence’ that extend from: (i) pre-encounter context, which is the time period where there is a risk of interaction with a predator, but no predator is actually present; (ii) post-encounter threat is when a threat is detected, but there is no direct interaction between the prey and predator (e.g. the predator has not yet detected the prey) and (iii) circa-strike threat is the stage where the predator starts to attack the prey with the intention of capture and consumption [11,45]. These levels of threat imminence are also played out in the context of homeostatic threats such as starvation, and energy needs and have their own distinct strategies, behaviors, computations and psychological states [6^●●]. Further, these levels of threat and their defensive responses are modulated by other survival circuits [7]. The red and green dotted line refers to the excitation or inhibition of other defense responses. Note, for simplicity, other physiological responses (e.g. autonomic and endocrine systems) are not in the model.