By Christian Jarrett

So entrenched is the association in our culture between coffee and ideas of arousal, ambition and focus that merely thinking about, or being reminded of, the drink is enough to increase the body’s arousal levels, in turn provoking a more focused, literal cognitive style. That’s according to Eugene Chan at Monash University and Sam Maglio at the University of Toronto Scarborough who, reporting their findings in Consciousness and Cognition, write that “… people may be more aroused simply after walking by a coffee shop. Not only would they be more aroused, but at a more downstream level, their decision making might shift as well.”

The intriguing results come from four studies involving hundreds of online and lab-based participants, but given the replication problems in the general area of “social priming” (concerned with how abstract ideas and sensory experiences can influence thoughts and behaviour, and vice versa), some readers may find that merely hearing about this new research is enough to elevate their pulse and alter their mindset to a more sceptical mode.

The four studies followed a similar pattern and no drinks were actually ingested. They started with participants being cued to think about either coffee or tea. In one study, they had to come up with advertising slogans for coffee or tea (depending on which group they were allocated to); in the other studies, they read either a mocked-up health news story about the benefits of drinking coffee or a version pertaining to tea. These reminders were then followed by a measure of the participants’ physiological arousal levels, either self-reported (they rated how alert, energetic and excited they were feeling) or based on their heart-rate. And finally, the participants completed a measure of their construal level – essentially how much they were thinking in a focused or literal way, or more abstractly. This final measure mostly took the form of categorising activities, such as deciding whether “making a list” is an example of “getting organised” (more abstract) or “writing things down” (more literal).

Overall, the results showed that thinking about and being reminded of coffee increased participants’ physiological arousal levels (whether self-reported or based on heart-rate), compared with thinking about and being reminded of tea, and in turn this greater arousal prompted a more literal, focused thinking style – that is, a lower, more concrete construal level.

One of the studies showed that this arousing, cognition-altering effect of coffee reminders only played out for Western participants, not for participants from Eastern countries (recent immigrants to Canada and America from China, Japan and Korea) where coffee is less popular and does not have the same connotations related to energy, focus and ambition.

Another study showed that the cognition-altering effect of coffee reminders was enhanced by watching an exciting clip from the Fast and Furious movie and nullified by a clip from the less exciting House of Rock, which the researchers said bolstered the idea that the effect of the coffee reminders on thinking style was acting via the changes it induced in arousal.

The researchers noted that they were agnostic on whether these apparent effects of coffee reminders are advantageous or not – presumably it would depend on the circumstances. They called for more research to explore the implications of their findings, concluding that “our research adds to the literature documenting that the foods we eat and the beverages we drink do more than simply providing nutrition or pleasure. Mere exposure to or reminders of them can affect how we think.”

Readers might understandably question the practical significance of the effects documented here (for some perspective, the average heart rate for the coffee group was 76 beats per minute, compared with 70 beats per minute for the tea group), and will probably want to see the findings replicated before reading too much into them. Another issue was that there was no baseline condition, rather the coffee reminders were always compared to tea reminders. Therefore one could arguably interpret the results as showing that reminders of tea reduce arousal and induce a more abstract thinking style, rather than that coffee increases arousal and induces a concrete thinking style. Chan and Maglio acknowledged the need for follow-up research, writing “we await further work to replicate our basic effects, providing practitioners and researchers further credence in the validity and reliability of the findings.”

Anyone else feeling thirsty?

—Coffee cues elevate arousal and reduce level of construal

Christian Jarrett (@Psych_Writer) is Editor of BPS Research Digest