Background music can make us less cautious

By Emma Young

Background music is a feature of most people’s everyday lives. Whether it’s while driving, at the gym, at home, or even at work, we often have music playing while we’re doing something else. Research into precisely how this affects our behaviour, emotions and cognitive processes have provided mixed findings, however. One of the reasons, argue Agustín Perez Santangelo at the University of Buenos Aires and colleagues, is there are so many variables, both in terms of the type of music used in the studies, and also the aspects of performance being measured — so it’s no wonder that results have been inconsistent.

Santangelo’s team decided, therefore, to explore changes in just one musical variable — tempo — and to look for effects on two individual aspects of decision-making: speed and accuracy. And they report in their paper in the Journal of Experimental Psychology: General, that background music did indeed have an effect: it made the participants less cautious.

A total of 32 participants completed a series of tasks three times: in silence, and while listening to the classical, instrumental piece The Flight of the Bumblebee by Rimsky-Korsakov, at a tempo of 40 beats per minute and also at 190 beats per minute (with all other musical features unchanged). This was the biggest difference in tempo that the team felt it was reasonable to use. (And the participants did give pretty much the same liking ratings for both versions.)

The tasks were of different types and levels of difficulty. There were two perceptual tasks (the participants had to decide whether a cloud of dots on a screen was moving to the left or the right, for example), a general knowledge task; a lexical categorisation task (a string of five to eight letters was displayed, and they had to decide whether it was a word or not); and also a task that involved repeatedly choosing which they preferred of two snack options (they had earlier rated 100 snacks; picking the one they had earlier reported liking better was taken as a correct response). For every decision, they were instructed to respond as quickly and accurately as possible.

In total, the researchers gathered data on just over 100,000 individual decisions. And the analysis threw up a few clear findings. First, the presence of music — vs silence — affected performance on all of the tasks. It led participants to make faster and also less accurate decisions.

Interestingly, tempo had no bearing on this: whether the music was fast or slow, this effect was the same. Some earlier studies have suggested that because a faster tempo increases physiological arousal, it “speeds” us up, too, quickening our responses. The participants in this study did report feeling more physiological arousal while listening to the fast vs slow version — but this did not translate into relatively faster responses.

So what might explain the findings? The researchers suspect that the background music caused a shift in the decision-making process itself — that it reduced the amount of data that the participants’ brains required to reach a decision. This would lead to what they found: quicker but less accurate responses. 

Is all background music likely to do this? The researchers used only one piece, so it’s impossible to know from this study. But the liking ratings did show that the participants weren’t too keen on it, whether it was fast or slow. It might be that the music induced a mildly negative emotional state, and it was this, rather than the music per se, that tweaked their decision-making. Other types of music might have different effects, then, as might other kinds of background noise.

One of the strengths of this study, compared with some others in the field, is that the team stripped the number of variables right down. This made it easier to explore the impacts of different experimental conditions. However, when we listen to background music in the real world, the variables are legion. The team suggests that perhaps background music has a negative impact on driving-related decisions, for example — but it’s not possible to directly extrapolate.

Still, the finding that background music can affect the process of reaching a decision is an interesting one. As the team writes, such music is “seemingly innocuous and ubiquitous” — but if, in some circumstances, it makes us less cautious, that’s worth exploring further.

Background music changes the policy of human decision-making: Evidence from experimental and drift-diffusion model-based approaches on different decision tasks.

Emma Young (@EmmaELYoung) is a staff writer at BPS Research Digest