What is "psychophysical parallelism"

n. (cx philosophy English) The theory that mental and bodily experiences occur in tandem with each other, but without any type of causal interaction.

Psychophysical parallelism (or parallelism) is the philosophical theory that mental and bodily events occur together, without any causal interaction between them. As such, it affirms the correlation of mental and bodily events, but denies any causal relationship. On this view, mental and bodily phenomena are independent but inseparable– like two sides of a coin. The theory is a third possible alternative of relation between mind and body, between interaction (eg, dualism) and one-sided action (eg, materialism or epiphenomenalism).