Consumer Behavior: How People Notice, Want, Choose and Regret

You walk into a supermarket for milk and walk out with milk, a chocolate bar and a magazine. Ask yourself afterwards what the shelf looked like and you could not draw it. You did not read forty labels. You did what everyone does: looked at a fraction of what was there, went to the familiar, glanced at what other people were taking, and decided in a few seconds.

Consumer behavior is the study of how that actually happens, as opposed to how a spreadsheet says it should. It sits where marketing meets psychology. Its famous results fill popular books, and a good share of them have not survived careful checking. Part of what a graduate learns is how to tell which is which.

You notice far less than you think

Sharp vision covers only a small patch at the centre of your gaze. The rest of the scene is filled in by expectation. That is why people can look straight at something and not see it. In the best-known demonstration, Daniel Simons and Christopher Chabris asked viewers to count basketball passes in a video; about half of them did not notice a person in a gorilla suit walk through the middle (Perception, 1999). The effect has been repeated many times. The lesson for marketing is blunt: attention is the scarce resource, and the shopper is not looking where you hope.

A cousin is change blindness. If a change happens during a blink, a cut or a flicker, people miss large differences. Ronald Rensink and colleagues built a "flicker" method in 1997 that shows how hard it is to spot a change when a blank screen separates two versions. Try it: one item on the shelf changes colour. Find it.

With the blank on, most people take several cycles; with it off, the moving colour jumps out. A real shelf has hundreds of items and no obvious blank, but every blink, glance and pause plays that role. For brands this means a distinctive colour or shape is not decoration: it is how the product gets noticed at all (see Brand Management, 34/60).

Learning to want, and the decision journey

People are not born wanting a brand. They learn to. Three mechanisms matter. Repetition: Robert Zajonc showed in 1968 that merely seeing something again makes people like it a bit more, and the "mere exposure" effect has held up in a large meta-analysis by Robert Bornstein (1989), with the effect modest and fading if repetition is overdone. Association: pair a brand with a feeling people already like (a sunny beach, a trusted face) and the feeling rubs off, a form of conditioning. Memory: you can only choose what comes to mind. Researchers call the handful of options a shopper actually thinks about the consideration set.

Then comes the decision journey. The textbook picture is a funnel; in 2009 McKinsey consultants (Court, Elzinga, Mulder and Vetvik) argued it is a loop with four moments: initial consideration, active evaluation, purchase, and the experience after, which feeds back into the next consideration. For many everyday goods the journey is nearly empty: you grab the usual. The more a purchase costs, or the more risky it is, the longer and more deliberate the journey becomes. A graduate asks first how much of a journey this product has at all.

Moment	What happens	What it implies
Consideration	A few options come to mind	If you aren't recalled, you aren't chosen
Evaluation	Comparing, asking, searching	Reviews and friends matter most here
Purchase	Often fast, at the shelf or screen	Availability and defaults decide
After	Use, satisfaction or doubt	Feeds the next round

Choice: is more always worse?

The most-quoted study in the subject is the "jam study" of Sheena Iyengar and Mark Lepper (2000). In a supermarket, a table with 24 jams drew more people to stop than a table with 6, but about 3% of the people at the big table bought, against about 30% at the small one. The conclusion, that too much choice paralyses, became a bestseller idea (Barry Schwartz, The Paradox of Choice, 2004).

Then researchers tried to repeat it. In 2010 Benjamin Scheibehenne, Rainer Greifeneder and Peter Todd pooled 50 experiments and found that the average effect of more options was close to zero, with large differences between studies. Alexander Chernev and colleagues (2015) ran their own meta-analysis and argued the effect is real under conditions: when the options are hard to compare, when the shopper has no clear preference, and when the set is large and complex. So the honest reading: choice overload happens, but it is not a law, and the famous 3% versus 30% was not a typical size.

A simple model shows why both can be true. Suppose every option has a random value for you between 0 and 1. The best of n options has expected value n ÷ (n + 1): more options always raise the best you could find, with diminishing returns. But looking costs effort. Subtract a small cost per option and a sweet spot appears.

At half a point per option the best number is 13, but the curve is flat near the top, so a shelf with 6 or with 24 is within a few points of 13. The model does not say the jam study was wrong. It says the effect depends on effort, which is why big, confusing sets can hurt while familiar categories (milk, toothpaste) usually do not.

Other people decide with us: reference groups and social proof

A reference group is anyone whose view you use as a yardstick: family, colleagues, strangers who look like you. Robert Cialdini called the habit of using other people's behaviour as evidence social proof (Influence, 1984). It is sensible: if a restaurant is full, it is probably good. The risk is that proof can be circular, with each person copying the last.

Matthew Salganik, Peter Dodds and Duncan Watts tested this in 2006. 14,341 participants downloaded unknown songs from an online "music market". Some saw others' download counts; some did not. When people could see the counts, the popular songs got much more popular, the unpopular ones less, and which songs won differed from one run of the experiment to the next. Quality mattered a little (the best songs rarely did badly and the worst rarely did well), but luck early on was amplified. The next model captures the mechanism: 200 people choose in turn between two equally good options.

With no copying, every world ends near 50-50. Turn the influence up and the worlds spread out: in some, A takes over; in others, B, though the two options are identical. Success looks like quality from inside any single world. This is why marketers pay for early reviews, why "bestseller" labels work, and why a hit can be partly an accident.

The same ad, a different country

Consumers carry a culture. Geert Hofstede's 1980 study, based on IBM employee surveys in more than 50 countries (about 117,000 matched samples, 1967–73), grouped national differences along dimensions such as individualism versus collectivism, power distance and uncertainty avoidance. In his published scores, the United States rates about 91 on individualism, while countries like Hong Kong sit near 25. Marketers used this to guess whether an ad should talk about "you" or about "family".

Treat it as a hypothesis, not a map. Critics such as Brendan McSweeney (2002) challenge the method: the sample was one company and mostly men, countries are not uniform, a national average says little about any individual, and the data is old. A useful rule: use culture to ask a question ("would this joke, colour or family role mean the same here?") and then test it with local customers. Many tales about product names that "meant something rude" abroad are urban legends, so check before repeating one.

Famous claims, checked

The field has a pile of results that everyone has heard. Some were real, some shrank, some were never what they were said to be. Guess first; then see.

Notice how often the number in the story is the part that fails, while a smaller, real effect remains. Two lessons for working marketers: ask for the sample and whether anyone repeated it, and be wary of any single "X% of decisions" figure.

After the purchase: regret and doubt

Leon Festinger's cognitive dissonance (1957) explains why people, after a costly purchase, seek reasons they chose well and avoid evidence they didn't: the mind dislikes holding "I chose it" and "it was a mistake" together. Sellers use this with follow-up messages that confirm the choice. Regret has a time pattern too. Thomas Gilovich and Victoria Medvec (1995) found that in the short run people regret what they did, but looking back over a long time they regret what they did not do.

On the shelf, regret and choice interact. Barry Schwartz and colleagues (2002) found that "maximisers", who check everything for the best, report less satisfaction and more regret than "satisficers", who take what is good enough; the work is correlational and later studies are mixed, so treat it as a tendency, not a verdict. Returns policies, free trials and reviews are all ways of lowering the price of regret.

What a graduate just sees

• The shopper looks at very little; the first job of a pack or a page is to be noticed.
• Most everyday buying is quick and habitual; the "journey" is short for cheap, familiar things.
• Repetition and association build liking before any argument is heard.
• More choice is not automatically worse; it depends on effort and on whether people know what they want.
• Crowds amplify luck: popularity is partly a story about earlier popularity.
• Culture is a question to test locally, not a stereotype to assume.
• When a study has a dramatic number, check whether it was repeated.
• People regret, and sellers can lower that cost by making returns and reassurance easy.

Where it shows up next

• Brand Management (34/60): mental availability is the consideration set, and distinctive assets are the answer to attention.
• Pricing (34/61): how people perceive a price, from anchors to "is this fair".
• Marketing Research & Analytics (34/59): how to ask, test and check whether a finding replicates.
• Behavioral Economics (34/46): the formal sister of this subject, with the same replication debates.
• In the world: why retail shelves are laid out as they are, why apps rank "most popular", and why returns policies exist.

If you want to go deeper

• 📘 Textbook. Michael Solomon, Consumer Behavior: Buying, Having, and Being (Pearson). The standard undergraduate text, with many applied cases.
• 📘 Textbook. Wayne Hoyer, Deborah MacInnis and Rik Pieters, Consumer Behavior (Cengage). More research-focused.
• 📘 Gentler. Robert Cialdini, Influence (1984; revised editions). Readable and full of examples. Daniel Kahneman, Thinking, Fast and Slow (2011) is the companion, though read it knowing some of its cited priming studies have been questioned.
• 🌐 Free course. MIT OpenCourseWare 15.810 Marketing Management covers the consumer side in its middle sessions; there is no single free consumer-behavior course I could confirm, so pair it with the books.