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Narrator: We judge people by what they choose, what they eat, buy, watch, even who they vote for. But our snap inferences often miss a crucial detail, how many options they had to choose from. A 2025 paper by Chicago Booth’s Beidi Hu and her co-authors shows that observers routinely overlook the size of the menu behind a choice, skewing how we read other people’s preferences.
Beidi Hu: So this project started from something that we probably all do in everyday life. We all make guesses about what other people like based on the choices they make, right? For example, if I see that you ordered salad for lunch today, I might assume you must really like salad. Or if we know that someone voted for a certain candidate, we might think that it says something deep about what they value. The past research in psychology, in consumer behaviors suggest that, well, people tend to over interpret others’ choices. Meaning that we tend to read more into others’ choices than we probably should. And that got us thinking about this idea that, well, maybe people are focusing too much on the choice itself and not as much on the context around the choice. And one of the most obvious, but probably easily overlooked aspect of a choice context is just how many options someone had to begin with, right? And that’s what we refer to as choice set size.
Narrator: Choice set size is simply how many options someone had. Picture an ice cream shop. With 10 flavors, you are more likely to find something you truly love down with just two. So when someone walks out with chocolate, the meaning of that choice, the inference that you can draw depends on the size of the menu.
Beidi Hu: If that person picked chocolate out of 10 different flavors, that probably reflects a pretty strong preference. But if that person picked chocolate out of two different flavors, we’ll probably derive much less meaning from that, right? So choice set size basically influences how much a choice can reveal about our preferences.
Narrator: The researchers ran six online experiments with more than 10,000 participants. In the first, participants read a simple restaurant scenario about ordering a side dish. They were randomly assigned to make a choice themselves or to observe someone else’s choice. And the choice set size was randomized so the menu offered either two or six side dishes. After the choice, participants either rated how much they liked their own pick or predicted how much the other person would like theirs. This core design served as the template for the remaining studies.
Beidi Hu: And the basic finding is that when people choose for themselves, having more options matters, right? If you get to pick from six different options rather than two different options, it’s just more likely that you will get something that you like a lot, and people report exactly that. But when observing others’ choices, when judging others’ choices, people don’t take that into account as much. And we think this is in part because people largely assume that others’ choices reflect a stable preference regardless of how many options are there in the first place.
Narrator: In short, the studies show that choice set size affects how much people like their own selections. Larger menus make closer matches more likely. But more interestingly, when judging other people’s choices, observers pay much less attention to set size and underestimate how strongly it shapes their liking. The implication reaches anywhere choices are made, from shopping and hiring to philanthropy and even politics.
Beidi Hu: In a two party system, when someone votes for a candidate, we might think of that vote as a pretty strong signal of support. But when there are only two options on the table, sometimes these votes might be more about rejecting the alternative rather than endorsing the chosen candidate. And if observers neglect the role of choice set size, as in if the observers neglect the fact that there are only two options available, they might assume that, well, these votes must reflect strong preferences. And that might lead us to think that others are more different from us than they actually are, which might potentially shut down opportunities for compromise or seeking common ground. And over time, this type of misperception or misread signals can potentially perpetuate polarization.
Narrator: A simple mental nudge makes us smarter observers. Before you judge the choice, ask how big the menu was. When we see the context, we see the person more clearly and we make better decisions about products, policies, and people.
