Despite increasing public debate over the appropriateness of sex in advertising, sexual imagery and high status individuals continue to be used by marketers to sell products.

However, answering why sexual imagery has proven so influential in advertising receives conflicting answers. Social constructionists argue that these consumer preferences are primarily shaped by people’s experiences within particular social, economic and historic contexts. Conversely, evolutionary psychologists argue that such stimuli satisfies ancient biological drives that evolved to prioritise useful social information.

In the online journal PLOS One, Mehmet Yavuz Acikalin and his colleagues have recently published a unique experiment which helps provide an answer. To explore the origins of our consumer preferences, the researchers conducted a pseudo-advertising campaign on non-human primates.

Monkey Ads

Acikalin and his colleagues tested whether pairing common brand logos with either sexually provocative images or alpha males would lead monkeys to prefer these brand logos.

Rhesus macaque monkeys were used for the experiment, which are old world monkeys native to Central and South Asia. Rhesus macaques form into large mix-sex groups and strict dominance hierarchies. The researchers argue their highly complex social interactions make them ideal for understanding social cognition and behaviour in primates.

We humans diverged from old world monkeys on the evolutionary tree of life around 25 million years ago. If these monkeys show a preference for brand logos that have been paired with sex and social status cues, the authors claim this would support such consumer preferences being evolutionary ancient (rather than a mere social construction).

Using non-human primates allowed for a controlled experiment, where the researchers could rule out the effect of culture and previous engagements with such brands. Additionally, the experimental design allowed the researchers to conduct extensive testing that wouldn’t be feasible in laboratory experiments with humans.

Ten adult rhesus macaques were used for the study, five of each sex. The monkeys participated in the experiment by interacting with a touch-screen interface within their enclosures. The monkeys were shown an image of a real-world brand logo, alongside an image of a monkey which formed the monkey adverts.

Three types of images were used for the adverts: a dominant or subordinate male’s face, or a female monkey’s ‘hindquarters’. Other logos were paired with a scrambled image containing no social information as a control. The monkeys were trained to use the equipment beforehand, and were rewarded with fruit juice whenever the monkey chose a logo on the screen, regardless of their preference.

Sex sells

The researchers found that following the pseudo-advertising campaign, the monkeys developed preferences for brand logos that had been paired with images of male faces and females’ behinds.

As predicted, the females showed no preference for the brands paired with the faces of low status males (to reference TLC, female macaques don’t want no scrubs).

Contrary to their expectations however, the male monkeys also formed a preference for brand logos paired with low dominance males. The researchers speculate that this may be due to males being attentive to low status males who may try to use aggression to climb the monkey hierarchy.

Yavuz Acikalin and his colleagues state the study shows preferences for brands advertised with sex and status cues can emerge independent of cultural learning and imitation found only in humans.

The authors note that although their results support an evolutionary perspective on why we sex is used in advertising, this does not mean that socialisation and culturally-defined gender roles do not influence our consumer behaviour. Rather, they argue that there’s likely strong evolutionary drives behind our consumer preferences, which can either be amplified or suppressed through socialisation.

Although several hundred trails were conducted, a key limitation of the study is that only 10 monkeys were involved in the experiments. I wouldn’t usually comment on a study with such a small sample size. However, there are other reasons why monkeys may also respond to the social drives which advertisers tap into.

Fundamentally, rhesus macaques and other monkey species share with humans similar neural mechanisms that have been linked to social decision making and evaluation. Also, a previous study of a similar nature found that rhesus macaques are willing to sacrifice rewards to see naughty monkey photos.

A mistake to avoid is extrapolating findings from other species to humans which do not apply. However, the rationale for the experiments and the inferences the authors make appear well justified.

A potential limitation of the study is that it assumes sex is an effective way to sell products to us homosapiens. However, I understand there’s considerable debate here, and that the reality may be more nuanced (especially in an age of shifting social norms and consumer preferences).

These points aside, we may be able to draw a lesson from this study.

Although our evolved psychological dispositions helped our great ancestors survive and thrive by attending to opportunities for sex and status enhancement, Yavuz Acikalin and his colleagues suggest that such motivations left unchecked can be detrimental to our mental health (and our bank balance). Being aware of this means we can step back and evaluate what we really want to achieve through our consumer purchases.

In summary, we’d all surely benefit from knowing how deep-seated evolutionary motives shape our consumer behaviour.

Written by Max Beilby for Darwinian Business