Fish do not feel pain and its implications for understanding phenomenal consciousness.

Feeling pain requires specific neural architecture that fish lack. While humans readily attribute subjective experience to animals that respond to noxious stimuli, the neural properties necessary for phenomenal consciousness—the subjective feeling of sensory stimuli—are present in mammals and birds but absent in fish. Fish respond to noxious stimuli reflexively and with limited behaviors, not through conscious awareness. The paper proposes a set of fundamental neural tissue properties required for experiencing affective states and concludes that fish do not feel pain.

Study at a glance

Abstract

Phenomenal consciousness or the subjective experience of feeling sensory stimuli is fundamental to human existence. Because of the ubiquity of their subjective experiences, humans seem to readily accept the anthropomorphic extension of these mental states to other animals. Humans will typically extrapolate feelings of pain to animals if they respond physiologically and behaviourally to noxious stimuli. The alternative view that fish instead respond to noxious stimuli reflexly and with a limited behavioural repertoire is defended within the context of our current understanding of the neuroanatomy and neurophysiology of mental states. Consequently, a set of fundamental properties of neural tissue necessary for feeling pain or experiencing affective states in vertebrates is proposed. While mammals and birds possess the prerequisite neural architecture for phenomenal consciousness, it is concluded that fish lack these essential characteristics and hence do not feel pain.