An intelligence test score measuring adaptive learning capacity, expressed as the chronological age at which one’s performance level is average. Used to calculate IQ along with chronological age.
Example: If an adult is able to solve problems only as well as a grade-schooler, what do the adult and the child have in common?
Grinnell, R. (2008). Mental Age. Psych Central. Retrieved on November 28, 2015, from http://psychcentral.com/encyclopedia/2008/mental-age/