Definition of "epiphenomenal"

epiphenomenal

/ˌɛpɪfɪˈnɒmɪnəl/

adjective
comparative more epiphenomenal, superlative most epiphenomenal
1. Being of secondary consequence to a causal chain of processes, but playing no causal role in the process of interest.
  Quotations
  An organism's consciousness is epiphenomenal to its behavior, and its behavior is determined by unconscious calculations.
  1981, William Irwin Thompson, The Time Falling Bodies Take to Light: Mythology, Sexuality and the Origins of Culture, London: Rider/Hutchinson & Co., page 58
  To this day, critics of materialism regularly recite the tenacious canard that the model crudely counterposes ‘economic’ factors to ‘culture, ideology and mentality’ […] That for materialism, thought is epiphenomenal froth. This is bogus.
  2022, China Miéville, chapter 2, in A Spectre, Haunting: On the Communist Manifesto
2. (philosophy, psychology) Of or pertaining to a mental process that occurs only as an incidental effect of electrical or chemical activity in the brain or nervous system.
  Quotations
  If qualia are epiphenomenal in the standard philosophical sense, their occurrence can't explain the way things happen (in the material world) since, by definition, things would happen exactly the same without them.
  2002, Daniel Dennett, “‘Epiphenomenal’ Qualia?”, in Neil Campbell, editor, Mental Causation and the Metaphysics of Mind: A Reader, Broadview, page 211