A new paper in the Journal of Consumer Research looks at subliminal influences on consumer decisions, and Science Daily has a great write-up. In the first study, experimenters tested the effect of visual stimuli on preferences regarding delayed gratification:
Li asked participants to act as “photo editors of a magazine” and choose among either appetite stimulating pictures of food or non-appetite stimulating pictures of nature. A control group was shown no pictures at all. All were then asked to participate in a lottery that would either pay them less money sooner or more money later.
Those who had been exposed to the photos of food were almost twenty percentage points more likely to choose the lottery with the chance of a smaller, more immediate payoff than those who were exposed to the photos of nature (61 percent vs. 41.5 percent) and eleven percentage points more likely to choose the short-term gain than those who had not been exposed to any stimulus (61 percent vs. 50 percent).
The second study tested the effect of odor on consumer spending:
Another experiment used a cookie-scented candle to further gauge whether appetitive stimulus affects consumer behavior. Female study participants in a room with a hidden chocolate-chip cookie scented candle were much more likely to make an unplanned purchase of a new sweater — even when told they were on a tight budget — than those randomly assigned to a room with a hidden unscented candle (67 percent vs. 17 percent).
I have a feeling J.Crew is stocking up on cookie candles as we speak…
Yaawwwn. According to conventional wisdom, we get sleepy after Thanksgiving dinner because of the high tryptophan content in turkey. Tryptophan is an essential amino acid that serves as a chemical precursor for serotonin, a vital neurotransmitter involved in mood and wakefulness.
There are many studies demonstrating serotonin’s sedative effects, but I want to take a minute to highlight a paper that implicates serotonin in social cognition.
Wood et al. measured social behavior using a monetary prisoner’s dilemma game in which subjects thought they were playing against other people (in fact they were playing against a computer that utilized a standardized tit-for-tat strategy against each subject). If subjects were kept on a diet low in tryptophan, they demonstrated less cooperativity in their decision making. When subjects were given a drink with high tryptophan content before playing the prisoner’s game, they were more likely to cooperate with their automated partners.
It’s exciting to think that that something as mundane as diet can significantly modulate economic decision making. Maybe it will inspire CEOs to start dosing the the water cooler with tryptophan before attempting to broker a delicate merger. However, such scenarios are not entirely analagous to the study at hand because Wood et al. deprived subjects of tryptophan prior to behavioral testing, whereas most adults are unlikely to enter an important business meeting on an empty stomach.
The title of this post is also misleading because there’s not much evidence that eating turkey increases the concentration of tryptophan in your brain. Zack Lynch of Brain Waves does a nice job of busting this myth, so I’ll just direct you there instead of re-hashing the argument.
First Slate tried to convince us that drug addiction is simply a bad habit. Now, in an article by Tim Harford, they are trying to convince us that addiction is actually rational. I can’t claim to understand all the economic theory behind the claim, but if you care to investigate, here is a link to the original proposal.