Lauren Marsh

Who they are

Marsh approached a consumer-psychology finding from a developmental direction, which is why the paper is worth more than another adult replication would have been.

Three studies. The first locates the ontogeny: the bias emerges at around age five, corresponding with milestones in self-concept formation. The second tests effort directly and finds no moderation by the amount invested, in five to six year olds. The third tests ownership and finds that ownership alone cannot explain why children value their creations more.

Taken together the paper does something unusual. It accepts the effect and dismantles both of its standard explanations, stating that the results are incompatible with existing theories of the bias, and proposes a link between a person's creations and their self-concept in their place. That is harder to publish and more useful than either confirming or overturning a headline.

Key papers

Marsh, L. E., Kanngiesser, P., & Hood, B. (2018). "When and how does labour lead to love? The ontogeny and mechanisms of the IKEA effect." Cognition, 170, 245-253. First author. Published online 25 October 2017, in the January 2018 issue, so the issue year is cited here.

Key ideas

Neither effort nor ownership is sufficient, on their evidence. See Psychological Ownership.

Age five is informative. The emergence alongside self-concept formation points at authorship rather than at exertion.

Scope matters both ways. A developmental sample does not settle the adult case, and this record says so wherever the finding is used.

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