Cover art for The Jam Study Does Not Say What Your Deck Says

Published: November 9th

The Jam Study Does Not Say What Your Deck Says

The famous result rests on four people. Stop cutting options on reflex.

Choice overload is the idea that more options make people less likely to pick any of them. It is the most quoted finding in product design, and the most misquoted.

Almost every deck that cuts a list reaches for one jam display in one grocery store. I have used that slide myself. The study is real. What it cannot carry is the weight the industry puts on it.

The famous ten to one result comes down to four people buying jam.

Two women in a farm shop each hold up a jar of preserves, turning them towards each other to compare, laughing, in front of shelves packed with jars.
Two jars, held side by side. That is the fix, and it is not the same as taking a shelf away.

1. Trimming the list because the list is long

What teams ship: A pricing page cut from nine plans to three, because nine felt like a lot.

Why it fails: The count on its own predicts almost nothing. Scheibehenne, Greifeneder and Todd pooled 63 conditions from 50 experiments, 5,036 people, and found a mean effect of 0.02. The interval ran from minus 0.09 to 0.12. That is zero with noise around it.

Ship instead: Treat the number of options as one dial out of four, not the diagnosis.

2. Quoting the ten to one ratio

What teams ship: The slide that says 30 percent bought from six jams and 3 percent bought from twenty-four.

Why it fails: Those percentages are 31 people and 4 people. The entire effect is four jam buyers. Scheibehenne later reran it in a German supermarket with 504 shoppers and measured 0.02.

Ship instead: Cite the sample out loud. It changes how the room treats it.

3. Cutting options when the real problem is comparing them

What teams ship: Fewer cards, each still impossible to read against the next.

Why it fails: Chernev, Böckenholt and Goodman pooled 99 observations covering 7,202 people and found four factors that decide whether a big set hurts. The two strongest were how hard the set is to compare, at 0.55, and what the user is trying to do, at 0.56. Complexity is about telling two options apart, not how many sit on the page.

Ship instead: Build the comparison. A good table beats a cull.

4. Cutting the same way for experts and for newcomers

What teams ship: One shortened list for everybody.

Why it fails: Being unsure what you want was a real factor, at 0.32. The 2010 review found the opposite running the other way too: people who know what they want do better with more options. Cut the list and you tax your best users to protect your newest.

Ship instead: Short default, full list one click away.

5. Ignoring how much work the user wants to do

What teams ship: A long list and no fast way through it.

Why it fails: The user's goal was the strongest factor of the four. Someone who wants to be done in ten seconds behaves nothing like someone who came to research. A 2025 study in NeuroImage timed it. When people liked the set, they picked from a large one faster. When they did not, the large set made everything worse.

Ship instead: Give them the exit. One recommended pick, and filters that cut the set in one tap.

What you cite, and what it holds up

The claimWhat the evidence supports
Fewer options always convert betterMean effect across 63 conditions is 0.02
30 percent against 3 percent31 people against 4, in one store
Six is the right number of optionsNo study supports a number
Too much choice paralyses peopleOnly when the set is hard to compare
Cutting the list helps everyoneIt costs users who know what they want

The audit, before you cut anything

  1. Can a user tell two options apart in one read? If not, the card is the problem, not the count.
  2. Do they have to hold the comparison in their head? Put it on the screen.
  3. Do these users already know what they want? Experts want the long list.
  4. Is there a fast way out for someone who wants to be finished? Add that first.

If all four are clean and the page still does not convert, cut. Cutting first is just the cheapest thing to do, which is why everyone reaches for it.

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