Love and fear in the times of sickness

Abstract

Sickness induced by gastrointestinal malaise or by microbial pathogens is more than a private experience. Sick individuals share their illness within their social environment by communicating their sickness to others. In turn, recipients of the communication respond with appropriate behavioral adaptations. Avoidance of sick individuals and the events associated with their sickness is advantageous for members of the group. However, these responses can conflict with the need for comfort or social support expressed by sick individuals. There is evidence that the relationship between the sick individual and its social environment involves neurobiological mechanisms that are similar to those that mediate social bonding. Despite their commonality the feelings of love and fear/disgust that are associated with the sociality of sickness have thus far been neglected by mainstream affective neuroscience.

Love and fear: A special issue

“…Fear, anxiety, vigilance and related states involve primitive responses. In response to chronic threats or disease, prolonged or intense reactivity can overwhelm the capacity to cope [ 1 ]. Moreover, chronic or unchecked fear and anxiety can be deadly.…”

“…The word love has various meanings, but the formation of selective connections and resultant perceptions of safety or trust are found at the core of most biobehavioral definitions of love. The same biological systems that supported social bonds and reproduction enhanced the capacity to overcome fear, stress and disease [ [1] , [4] ]. The absence of supportive social connections leaves social mammals, and especially humans, vulnerable to neuroendocrine and autonomic dysfunctions [ 2 ] and virtually every type of physical and emotional illness [ [1] , [5] ].…”

“…The same biological systems that supported social bonds and reproduction enhanced the capacity to overcome fear, stress and disease [ [1] , [4] ]. The absence of supportive social connections leaves social mammals, and especially humans, vulnerable to neuroendocrine and autonomic dysfunctions [ 2 ] and virtually every type of physical and emotional illness [ [1] , [5] ].…”

Back to the future of psychoneuroimmunology: Studying inflammation-induced sickness behavior

“…The recognition of sick individuals by the persons in their surroundings will affect social interactions. Hence, the sick individual's peers can then choose to provide care and comfort, but also to avoid or isolate the sick individual in order to prevent infection to other members of the group ( Dantzer, 2021 ). Changes in social behaviors of the sick individual's peers can also, ultimately, affect behaviors and feelings of the sick individual.…”

Social factors and the neurobiology of pathogen avoidance

“…Avoidance responses can range from changes in the social behaviour of infected hosts that affect their interactions with conspecifics (i.e. sickness behaviours [ 4 , 5 ]), to shifts in the behaviour of healthy hosts, which is the focus of this review. These modifications in behaviour can arise either: (i) by directly avoiding or removing visible parasites or (ii) more indirectly, by either avoiding individuals or altering interactions with individuals that may be infected [ 1 , 6 ].…”