Fear generalization and behavioral responses to multiple dangers

Animals often exhibit consistent-individual differences (CIDs) in boldness/fearfulness, typically studied in the context of predation risk. We focus here on fear generalization, where fear of one danger (e.g., predators) is correlated with fear of other dangers (e.g., humans, pathogens, moving vehicles, or fire). We discuss why fear generalization should be ecologically important, and why we expect fear to correlate across disparate dangers. CIDs in fear are well studied for some dangers in some taxa (e.g., human fear of pathogens), but not well studied for most dangers. Fear of some dangers has been found to correlate with general fearfulness, but some cases where we might expect correlated fears (e.g., between fear of humans, familiar predators, and exotic predators) are surprisingly understudied. While behavioral ecologists have long appreciated that animals exhibit consistent individual differences (CIDs) in ‘fear’ of predators, there are parallel, but smaller literatures on fear (i.e., avoidance) of other dangers, including parasites/pathogens, humans, moving vehicles, chemical stressors, and fire.A few studies (mostly in humans) examine correlations between aspects of the personality of an individual (e.g., its boldness/fearfulness, anxiety, or exploratory tendency) and its fear of other dangers.Neophobia, fear of novel situations, can be a particularly important source of variation in animal responses to novel dangers in the human-altered world. Thus, a key issue is the correlation between neophobia and other aspects of personality.Fear generalization, where fear of one danger (e.g., predators) is correlated with fear of other dangers (e.g., pathogens, humans, automobiles, etc.) has been well studied in humans for a small subset of dangers, but has rarely been studied in other animals.The possibility that experiences that cause an increase in fear of one danger cause a parallel increase in fear of other dangers is well studied in humans (e.g., post-traumatic stress disorder), but rarely studied in other animals.