Task complexity and problem-solving performance in younger and older adults.

In problems resembling the Twenty Questions game, older and younger adults were asked to discover the square or squares the experimenter had in mind from an array of squares. Complexity was varied in three conditions in which problems had 6, 8, or 12 bits of information. Task demands were increased in a fourth condition by imposing a 60-sec time limit. Contrary to a hypothesis drawn from prior results, no evidence was found that older adults select more efficient strategies as task complexity or demands increase. Both age groups maintained the same strategies; the less efficient strategies selected by the older persons were reduced in effectiveness as task complexity increased.