Costly Curves

The thin ideal turns big people into big spenders.

Posted May 25, 2017

Western cultures tend to associate thinness with beauty, health, self-discipline, success, and economic value. Research by Marisabel Romero and Adam Craig, recently published in the Journal of Consumer Research, shows that these associations can have an unconscious effect on consumer behavior and that outcomes may differ between people of various sizes. While thinness should trigger positive stereotypes, these associations may have a negative effect on the decisions of high-BMI individuals whose body image contrasts the ideal. This was investigated in a series of studies. 

In one of the reported experiments, participants were primed by having to match images of either thin or wide human-like shapes to neutral visual descriptors (e.g. “clear vs. dark”). They then had to read two ostensibly unrelated scenarios about a frugal lifestyle (“being very careful about what to buy”) and an indulgent lifestyle (“buying items which make them happy, rather than those which meet their practical needs”) and evaluated whether they found each lifestyle appealing. Participants’ BMI was calculated based on information about their height and weight obtained before the study. As the researchers expected, results showed that high-BMI participants preferred an indulgent lifestyle after seeing a thin shape. A follow-up experiment that involved a real spending decision with a choice between a less expensive generic bottle of water and a more expensive bottle of “designer” water produced similar results.

Journal of Consumer Research, Romero & Craig (2017)
Source: Journal of Consumer Research, Romero & Craig (2017)

What is the mechanism underlying these findings? The authors of the research reckoned that financial self-efficacy may be a key variable that can explain the link between thinness primes and indulgent spending among high-BMI individuals.  This occurs because exposure to the thin ideal should result in feelings that one lacks control and thus lower financial self-efficacy for high-BMI individuals.

To investigate this hypothesis, the researchers conducted another experiment. This time, the thin versus wide priming task was followed by a scenario asking participants about their typical shopping behaviors, specifically whether they would pay for a hypothetical electronics purchase immediately with a credit card that would take three months to pay off or wait three months to buy it with cash. Subsequently, they answered questions related to financial self-efficacy (e.g. “Compared to other people, I can stick to a spending budget very well”).

Results of the study showed that high-BMI individuals preferred to use a credit card after exposure to the thin shape. Additionally, this group also felt lower financial self-efficacy after seeing a thin shape. The opposite was true for the low-BMI group, which had higher ratings of self-efficacy after being primed with thin shapes. 

“Our studies confirm that body shapes are powerful cues that can influence consumer spending preferences,” the authors conclude. “Marketers have long used slender models, forms, and designs to promote economic and social benefits. However, their design decisions might lead overweight consumers, who lack identification with idealized standards, to make more indulgent spending decisions.”

While we should expect these findings to have implications beyond the stimuli used in this research, there is a timely example of bottle shapes that has recently hit the supermarket shelf. As part of their Campaign for Real Beauty, Dove has launched limited edition body wash bottles of varying shapes, designed to empower consumers by providing bottles that “suit” their body type. The research reported in this article could provide the body-bottle matching campaign with both validation and a warning, as mismatches may have unintended effects.


Romero, M., & Craig, A. W. (2017). Costly curves: How human-like shapes can increase spending. Journal of Consumer Research, 44(1), 80-98.