Origin of negativism
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
a tendency to be or a state of being unconstructively critical
any sceptical or derisive system of thought
psychiatry refusal to do what is expected or suggested or the tendency to do the opposite
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Online Etymology Dictionary, © 2010 Douglas Harper
A tendency to do the opposite of what one is requested to do, or to resist stubbornly for no apparent reason.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.