Given how many of us listen to music while studying or doing other cerebral work, you'd think psychology would have a set of clear answers as to whether the practice is likely to help or hinder performance. In fact, the research literature is rather a mess (not that that has deterred some enterprising individuals from making bold claims).
There's the largely discredited "Mozart Effect" – the idea that listening to classical music can boost subsequent IQ, except that when first documented in the 90s the effect was on spatial reasoning specifically, not general IQ. Also, since then the finding has not replicated, or it has proven weak and is probably explained as a simple effect of music on mood or arousal on performance. And anyway, that's about listening to music and then doing mental tasks, rather than both simultaneously. Other research on listening to music while we do mental work has suggested it can be distracting (known as the "irrelevant sound effect"), especially if we're doing mental arithmetic or anything that involves holding information in the correct order in short-term memory.
Now, in the hope of injecting more clarity and realism into the literature, Manuel Gonzalez and John Aiello have tested the common-sense idea that the effects of background music on mental task performance will depend on three things: the nature of the music, the nature of the task, and the personality of the person. "We hope that our findings encourage researchers to adopt a more holistic, interactionist approach to investigate the effects of music (and more broadly, distractions) on task performance," they write in their new paper in Journal of Experimental Psychology: Applied.
The researchers recruited 142 undergrads (75 per cent were women) and asked them to complete two mental tasks. The simpler task involved finding and crossing out all of the letter As in a sample of text. The more complex task involved studying lists of word pairs and then trying to recall the pairs when presented with just one word from each pair.
Each task was performed while listening to one of two versions of a piece of elevator-style instrumental music – composed for the research – or no music. One version of the music was more complex than the other, featuring additional bass and drum tracks (both versions are available via the Open Science Framework). Also, depending on the precise experimental condition, the music was either quiet or louder (62 or 78 decibels). The participants also completed part of the "boredom proneness scale" to establish whether they were the kind of person who likes plenty of external stimulation or not (as measured by their agreement with statements like "it takes a lot of change and variety to keep me really happy").
Participants' performance was explained by an interaction between the task, the music, and their preference for external stimulation. When performing the simpler task, participants not prone to boredom did better while listening to complex music than simple music or no music, whereas boredom prone participants showed the opposite pattern, performing better with no music at all or simple music. In terms of volume, the low boredom prone were better with quiet complex music, whereas the boredom prone did better with louder complex music.
The researchers' explanation is that for low boredom people who aren't so keen on external stimulation, the quieter, more complex music provided just enough distraction to stop them from mind wandering from the simple task, thus boosting their task focus and performance. In contrast, the more boredom prone participants who like external stimulation tuned in too much to the complex music and were overly distracted by it, thus performing worse than when working in silence.
For the more complex task, the precise nature of the music (its complexity and volume) made no difference to results. But people low in boredom proneness benefited from having any kind of music in the background (the researchers aren't sure why, but perhaps there were mood or arousal-based benefits not measured in this study), whereas once again the boredom prone folk with a preference for external stimulation again actually performed better with no music.
Though these findings may seem counterintuitive, the researchers' explanation is that, for boredom prone people, the complex task provided adequate stimulation and background music interfered with this productive engagement. Supporting this interpretation, the more boredom prone participants outperformed their less boredom prone peers at the task in the no-music condition (and at an earlier, baseline cognitive test), suggesting they engaged better with the tasks (the researchers additionally noted that this result challenges the way that boredom as an emotion is usually seen as a bad thing, suggesting "it can predict constructive outcomes, such as better complex task performance").
If you consider yourself as prone to boredom and craving of external stimulation, a tentative implication of these findings – bearing in mind they are preliminary – is that you might be better off studying or do other cerebral work without music in the background, at least not music that is too complex. On the other hand, if you are less craving of stimulation, then paradoxically some background music could boost your performance. As the researchers stated: "we offer evidence against the commonly held belief that distractions like music will always harm task performance." They added, "our findings suggest that the relationship between music and task performance is not 'one-size-fits-all'. In other words, music does not appear to impair or benefit performance equally for everyone."
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Part of the problem with interpreting the results is in the ambiguity of the aspect of boredom proneness that the researchers looked at – "preference for external stimulation". Past research has generally considered boredom proneness to be associated with less desirable aspects of personality, such as having less self-control and being more impetuous, and this could fit with the idea that boredom prone participants in this research were more distracted by background music. However, as mentioned, the participants scoring higher on "preference for external stimulation" generally performed better at the tasks, thus raising questions about what aspect of personality and/or mental aptitude was really being tapped by this measure. It doesn't help matters that there was no direct measure of attentional control and focus in the study. (In terms of other relevant personality traits, prior research has found that introverts are more distracted than extroverts by highly arousing music).
Other obvious limitations include the question of how much the featured tasks resemble real-life challenges, and the fact that people often listen to music they know and like rather than unfamiliar, instrumental music.
Still, it's laudable that the current research attempted to consider how various factors interact in explaining the effect of music on mental performance. Gonzalez and John Aiello concluded, "we hope our research will serve as a starting point for more systematic investigation of music."