Research participants who were exposed to very convincing arguments about the desirability of frequent toothbrushing misrecalled how frequently they had brushed their teeth in the preceding two weeks. This best illustrate

Answer: Motivated forgetting

Explanation: Motivated forgetting is a psychological defence mechanism, and in particular the primary ego defence mechanism. It is in fact a repression that suppresses some unwanted memory, sometimes consciously, sometimes unconsciously. Suppression of unwanted memory is more often an unconscious phenomenon because the ego does not want to deal with the problem, that is, unpleasant memory and that memory is suppressed. Because unwanted memory is suppressed as uncomfortable, it is difficult to bring it back to consciousness because it causes unpleasantness during recall, so respondents could not accurately recall certain memories that were suppressed.