Creeping normality refers to the way a major change can be accepted as the normal situation if it happens slowly, in unnoticed increments, when it would be regarded as objectionable if it took place in a single step or short period. Examples would be a change in job responsibilities or a change in a medical condition.
Gradually trees became fewer, smaller, and less important. By the time the last fruit-bearing adult palm tree was cut, palms had long since ceased to be of economic significance. That left only smaller and smaller palm saplings to clear each year, along with other bushes and treelets. No one would have noticed the felling of the last small palm.
^McClellan, Bill (2013-10-27). "Normality creeping on". St. Louis Post-Dispatch. Retrieved 2014-08-03. Creeping normality is a term Jared Diamond used to describe the way major changes can seem normal if they happen slowly. This explains how things that a society might have found completely objectionable at one time can later appear to be quite ordinary.