Bizarreness Effect

What it is

Mark McDaniel and Gilles Einstein tested bizarre imagery as a memory aid across five experiments, published in the Journal of Experimental Psychology: Learning, Memory, and Cognition in 1986. Picture a dog riding a bicycle rather than chasing one. Bizarre images helped recall when bizarre and common items appeared in the same list. The advantage held across different presentation speeds, which counts against a simple story about extra attention, and the authors proposed distinctiveness as the explanation.

A 1995 follow-up by the same pair with three co-authors, titled "The bizarreness effect: it's not surprising, it's complex", found in its first experiment that the mixing itself produced the effect, rather than the small number of bizarre items in a list. A strange image needs ordinary ones beside it.

That is the point Hedwig von Restorff made in 1933 with word lists. In her experiment an odd item among similar ones was recalled by 70 per cent of volunteers, against 40 per cent for the same kind of item in a list where every entry differed. R. Reed Hunt, who had her German paper translated in 1995, argued that difference alone does not produce the effect; the similarity of the surrounding items does.

In effect

An advert that is strange in a break of ordinary ones has the background it needs to be remembered. A break, or a feed, in which every item strains to be strange begins to resemble the all-different list, where nothing stands out because nothing is alike. For a shopper, the image that sticks is the one that was odd in its setting, which says nothing about whether the product behind it is any good.

What it does not say

The studies found the advantage in mixed lists, so they do not show that bizarre material is better remembered on its own, and they do not show that a remembered image leads to a better choice. The work used laboratory lists and recall tests; nobody in these studies tested an advert or a shelf, so the application to advertising is an inference. The 1986 and 1995 papers were read here at the level of their abstract summaries.

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