"First is Best"

We experience the world serially rather than simultaneously. A century of research on human and nonhuman animals has suggested that the first experience in a series of two or more is cognitively privileged. We report three experiments designed to test the effect of first position on implicit preference and choice using targets that range from individual humans and social groups to consumer goods.

While this effect has been known about for many years, these researchers added an interesting component, an "Implicit Association Test (IAT)":

Each option within a pair was presented sequentially for 30-seconds and participants were forced to maximally consider both options. Immediately after each choice-pair was presented, participants completed a measure which assessed automatic preference for each option (an Implicit Association Test, or IAT) [22].


Regardless of the actual option, the one presented first compared to the one presented next was significantly more strongly associated with the concept ‘‘better’’ rather than ‘‘worse’’, F(1, 121) =20.20, p,.001; effect size r =.38 (Figure 1). There was no difference in self-reported preference for firsts versus seconds, F(1, 121) =.08, p= .78.

I was surprised to find there is no reference to "recency", "primacy" or "serial position" on the LessWrong Wiki. A search on LessWrong.com for "recency effect" turns up 8 posts that mention it but don't give it a thorough discussion as far as I can tell; "primacy effect" turns up 1 post about Rationality & Criminal Law; and "serial position" turns up nothing. Is there another name for this effect that I'm missing?

Wikipedia has some discussion of the serial position effect here, although from a quick skim it doesn't appear that they talk about preference at all.

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1 comment, sorted by Click to highlight new comments since: Today at 5:29 PM

Oddly enough, the IAT itself has major problems with the primacy effect - reversing the mappings causes confusion, producing a bias in the data that needs to be carefully excised. So, using the IAT to test the strength of the primacy effect in regards to something else is going to be extra-tricky.