Staplers, Snakes, and Sex

Do sexy pictures make men more likely to buy expensive sports cars? Possibly, according to Science Daily:

Irrelevant Image Of Attractive Woman Can Make A Man More Willing To Take Big Financial Risks

ScienceDaily (Apr. 5, 2008) — Attractive women plus cool cars equal brisk sales for auto dealers as men snap up those cars, prompted—or so advertising theory goes—by the association. But is the human male really so easily swayed? Can the irrelevant image of an alluring female posing by the merchandise actually encourage a heterosexual man to purchase it?

Possibly, according to a new study by Stanford researchers.

However, this new study (Knutson et al., 2008) has nothing to do with advertising and how it might influence the purchase of expensive merchandise.

Well then... Do sexy pictures make men more likely to take financial risks? The answer is yes, according to this AP story:

Sex and financial risk linked in brain

By SETH BORENSTEIN, AP Science Writer Sat Apr 5, 4:22 AM ET

WASHINGTON - A new brain-scan study may help explain what's going on in the minds of financial titans when they take risky monetary gambles — sex. When young men were shown erotic pictures, they were more likely to make a larger financial gamble than if they were shown a picture of something scary, such a snake, or something neutral, such as a stapler, university researchers reported.

The arousing pictures lit up the same part of the brain that lights up when financial risks are taken.

What sort of financial risk, you ask? Well, it turns out the risk in this particular study is not so big: $1.00 vs. $0.10, not exactly high-stakes trading on Wall Street.

"You have a need in an evolutionary sense for both money and women. They trigger the same brain area," said Camelia Kuhnen, a Northwestern University finance professor...

The study only involved 15 heterosexual young men at Stanford University. It focused on the sex and money hub, the V-shaped nucleus accumbens, which sits near the base of the brain and plays a central role in what you experience as pleasure.

OK, an evolutionary need for money? The sex and money hub? How exciting! Let's continue...

What did the experiment entail? On each trial, the participants saw one of three cues that predicted the category of a subsequent picture stimulus (household appliances, spiders & snakes, or erotic couples). Then the subjects waited for 2 sec before they chose between $1.00 and $0.10 in a guessing/gambling task. The researchers were particularly interested in what happened to the nucleus accumbens (aka the brain's "pleasure center"), which receives input from dopaminergic neurons in the ventral tegmental area. This mesolimbic dopamine pathway has been linked to reward, pleasure, and addiction.


Fig. 1 (Knutson et al., 2008). Cued risk task structure and regressor timing. Participants first viewed affective stimuli consisting of a shape (cue: circle, triangle, square) followed by a picture (picture: erotic couples, household appliances, snakes and spiders). Next, participants gambled by first waiting (anticipation), next choosing the high or low-risk option (choice), and finally viewing the outcome of their choice (outcome). Conjoined regressors modeled brain activation in response to affective stimuli (cue+picture) and during anticipation of choosing the gamble (anticipation).

So does the level of activity in the nucleus accumbens during the anticipatory phase predict the choice of a higher-risk gamble following the presentation of pleasant erotic stimuli? Why yes, it does.

Prediction analyses utilized logistic regressions to determine whether brain activation could predict financial risk taking. The first analysis indicated that viewing positive stimuli predicted subsequent shifts to the high-risk option, but gains on earlier high-risk trials predicted shifts to the low-risk option. A second analysis indicated that bilateral NAcc activation significantly predicted subsequent shifts to the high-risk option. A third analysis including stimulus and brain activation variables together indicated that viewing positive stimuli no longer significantly predicted shifts to the high-risk option, but NAcc activation did, suggesting a critical role for NAcc activation.

The bottom line?

...these results suggest that even incidental reward cues can act on anticipatory affect to alter financial risk taking. The findings have broad implications for understanding how affect might influence decisions, and for assessing the effectiveness of emotional persuasive techniques.

But didn't we already know that sex cues ruin men's decisiveness and spoil their decision-making abilities? Actually, that paper showed that lingerie sharpens the financial mind of high-testosterone males, resulting in more rational choices (taking the unfair option over nothing at all) in the ultimatum game.


If you're attending the upcoming meeting of the Cognitive Neuroscience Society in San Francisco, you can hear a talk by Dr. Knutson and others on Sunday, April 13:

The Power of Expectancy in the Human Brain

Brian Knutson - NUCLEUS ACCUMBENS ACTIVATION MEDIATES THE INFLUENCE OF INCIDENTAL REWARD CUES ON FINANCIAL RISK-TAKING

Daniela Schiller - OVERLAPPING NEURAL SYSTEMS MEDIATING EXTINCTION, REVERSAL AND REGULATION OF FEAR

Jack B. Nitschke - ANTICIPATING THE WORST: INVESTIGATING BRAIN MECHANISMS OF ANXIETY

Jon-Kar Zubieta - NEUROBIOLOGICAL MECHANISMS OF PLACEBO EFFECTS

References

Knutson, B, Wimmer G, Kuhnen C, Winkielman P. (2008). Nucleus accumbens activation mediates the influence of reward cues on financial risk taking. Neuroreport, 19(5), 509-513.

In functional magnetic resonance imaging research, nucleus accumbens (NAcc) activation spontaneously increases before financial risk taking. As anticipation of diverse rewards can increase NAcc activation, even incidental reward cues may influence financial risk taking. Using event-related functional magnetic resonance imaging, we predicted and found that anticipation of viewing rewarding stimuli (erotic pictures for 15 heterosexual men) increased financial risk taking, and that this effect was partially mediated by increases in NAcc activation. These results are consistent with the notion that incidental reward cues influence financial risk taking by altering anticipatory affect, and so identify a neuropsychological mechanism that may underlie effective emotional appeals in financial, marketing, and political domains.

Bonus! Bikinis and Intertemporal Choice:

Van den Bergh B, Warlop L (2008). Bikinis Instigate Generalized Impatience in Intertemporal Choice. J Consumer Res., in press. Free PDF preprint.

Neuroscientific studies demonstrate that erotic stimuli activate the reward circuitry processing monetary and drug rewards. Theoretically, a general reward system may give rise to nonspecific effects: exposure to “hot stimuli” from one domain may thus affect decisions in a different domain. We show that exposure to sexy cues leads to more impatience in intertemporal choice between monetary rewards. Highlighting the role of a general reward circuitry, we demonstrate that individuals with a sensitive reward system are more susceptible to the effect of sex cues, that the effect generalizes to nonmonetary rewards, and that satiation attenuates the effect.