Sheena Iyengar

Who they are

Iyengar studies how people make choices, and in particular what happens when the number of options grows. Her best-known paper, with Mark Lepper, was published in the Journal of Personality and Social Psychology in 2000. She is its first author, which is worth stating because retellings of the jam study often name the study without its authors, or credit the idea loosely to the field.

Her later work took the question into retirement saving. With Huberman and Jiang she analysed records for nearly 800,000 employees and found that participation in workplace retirement plans was higher where the plan offered a handful of funds. That study moved the idea from a supermarket table to a decision with long-term financial consequences, and it is one reason choice overload entered policy discussion as well as marketing.

This page records only what the papers and their published records state. Biography beyond the cited work is not given here.

Key papers

When choice is demotivating (2000), with Mark Lepper. A tasting table at a supermarket in Menlo Park, California, alternated between 6 jams and 24 over two Saturdays. More passers-by stopped at the larger display, 60 per cent against 40 per cent, but of those who stopped, nearly 30 per cent bought a jar after seeing 6 jams against 3 per cent after seeing 24. Two further studies in the same paper, on essay topics and on chocolates, found that choosing from 30 options produced less follow-through or less satisfaction than choosing from 6.

How much choice is too much? (2004), with Huberman and Jiang. Published in Pension Design and Structure: New Lessons from Behavioral Finance. Using data on nearly 800,000 employees, the study found higher participation in retirement plans that offered a handful of funds.

Key ideas

The central idea is that attention and decision can come apart. A large assortment can attract more people while converting fewer of them into buyers, because the act of choosing becomes harder as the options multiply. The jam study showed both halves in one design, which is what made it memorable.

The research that followed has tested how far the idea extends. Direct repeats, including a German supermarket version of the jam study reported in Benjamin Scheibehenne's 2008 doctoral work, did not find the effect. A 2010 meta-analysis by Scheibehenne, Greifeneder and Todd found a mean effect close to zero across 50 experiments. A 2015 meta-analysis by Chernev, Böckenholt and Goodman found the effect does appear under four conditions: complex option sets, difficult decisions, uncertain preferences and a goal of finding the best option. A working paper by Mark Dean and colleagues argues that more powerful tests find strong evidence of the effect.

Read together, that record supports the narrower version of the claim: large ranges can stall decisions when options are hard to compare and buyers are unsure what they want. It does not support a general rule that fewer options always sell more, which is the form in which the jam study is most often repeated.

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