Why Do People Buy What They Buy? How to Get Inside Your Customer’s Head

Human beings are remarkably similar to one another. We all have the same physical form, the same skeletal and muscular structures. The differences between us are minor—facial features, mental makeup—but very important.

Psychologists have identified key personality traits that distinguish human minds from each other. These traits are measurable and each person has a different combination of each of them. A lot can be learned about a person by how they score on these traits or fitness indicators as identified by Geoffrey Miller in his book Spent.

Almost every non-essential purchase that shoppers make--whether in the supermarket, online or in a department store--is bought for the purpose of increasing one or more of their personal fitness indicators. People buy certain products believing that ownership of the items will alter how other people perceive them and to improve their lives.

And, to some extent, it works. If you buy an expensive watch under the assumption that people who see you wearing it will assume you are intelligent and have good taste, this will have a measurable effect on your self-confidence and self-esteem.

Marketers can use information about these six traits to their advantage by demonstrating how people will react to customers who are wearing, consuming, or using a particular brand.

Why People Buy What They Buy

1. General Intelligence

General intelligence, the first key trait, is essential to appearing as a functional and desirable member of society, whether as a group or in a romantic pairing. This can increase society’s perception of a person as mentally and physically healthy and of high genetic quality.

We are constantly targeted with advertisements for products to make us appear more intelligent, whether they are brain foods, smart drugs (or brain-boosting vitamins), or smart toys for children. Ironically, many of these intelligence-boosting products also carry a high price tag—as we care about our social status, we are often happy to pay more for a status symbol such as an expensive watch.

2. Extraversion

Extraversion is the degree to which someone is outgoing, talkative, and socially confident. People with a high level of extraversion tend to enjoy leading, being active, and exerting self-confidence, meaning they often attract people to them and yet stand out from the crowd. The principal behind extraversion is the need to be seen in order to have a greater chance of being selected, much like mating dances for birds.

People may exhibit extraversion—or what they hope is extraversion—by wearing bright-colored clothing to project an outgoing personality that's not normally ascribed to them. This is often seen in films where the "plain" actor or actress dresses differently and then is suddenly perceived as popular and beautiful.

3. Openness

Openness is a trait that requires a balancing act; it relates to the curiosity, novelty-seeking, broad-minded aspects of people. We all have a natural comfort level of openness and tend to seek others of a similar nature. People with higher levels of openness than us are seen as threats, bizarre, eccentric, or even mad; those with lower levels are often viewed as dull or tedious. This has an evolutionary basis—we have to be open enough to form social groups but not so open that we become disruptive.

Many retailers and brand marketers try to demonstrate that as a result of buying a particular brand, we will seem more open and therefore become the center of attention. A lot of purchasing, however, has to do with fitting in. Having the only red sports car in a parking lot full of sensible black cars is a way to stand out, but potentially also brings the risk of being labeled as a loose cannon. The idea is not to just simply fit in, but to find a specific way of being distinctive without standing out too much.

4. Conscientiousness

Conscientiousness is the key to establishing long-term relationships, whether romantic or platonic. It is tied to reliability, integrity, trustworthiness, and punctuality. It is also one of the more recently evolved psychological traits, reflecting the self-control exerted by the frontal lobes of the brain over the impulsive, short-term instincts of the brain's limbic system. We tend to believe that those with the greatest apparent level of conscientiousness will make better long-term mates, providing more for the family unit and taking better care of offspring.

What we view as conscientious varies depending on our individual beliefs, whether it is personal grooming, ethical banking, or providing a healthy diet for our families. Marketers compete with each other to promote products that add to our conscientiousness trait, even if the perceived benefits are actually false, such as with many "healthy" breakfast cereals.

5. Agreeableness

Agreeableness is the basis of human altruism and social progression and, like openness, is desirable at different levels in different situations. While highly-agreeable people are amicable and good team players, they are also less likely to be leaders or to come up with outstanding ideas; in comparison, less agreeable people tend to be perceived as more dominant.

Therefore, some products are marketed to make us seem more agreeable and others are marketed to give us an edge over our colleagues or to follow the stereotype that less agreeable people are more sexually attractive. The more "agreeable" products tend to fall under the category of altruism or gift-giving, such as multipacks to be shared, for example.

6. Emotional Stability

Emotional stability is the ability to withstand pressure and recover from emotional setbacks. We tend to have a strong desire for other people to see us as emotionally stable, shopping for products that we think may improve our emotional stability (such as the recent rise in mindfulness products) or demonstrate to others our emotional stability.

Shoppers are often triggered to make purchases based on situational instability. For example, a shopper on a diet who shops on an empty stomach may see a cake at the bakery and buy it because their blood sugar level has dropped and their insula is crying out for sugar.

The Central Six Fitness Indicators Can Alter Purchasing Patterns

Shoppers often become reliant on particular products for reassurance, meaning that they are likely to become repeat purchasers and develop long-lasting brand loyalties. Products like luxury cars and watches, for example, may become products that shoppers rely on for reassurance of status. By maintaining the luxury image of their brands, marketers can perpetuate their product’s desirability as a fitness indicator.

These purchases aren’t only psychologically necessary for status—they are actually necessary. Success requires the trappings of status--a person will quickly lose status if he’s driving a ‘97 Ford Fiesta and his peers are all driving new Mercedes.