Abstract
This qualitative systematic review aimed to examine music-induced emotion effects on decision-making. Empirical articles published from 2006 to 2016 were searched for in PubMed and PsycInfo. Through the main search, 634 records were identified and 15 articles were included and analyzed according to the following categories: aims of the study, participants, study design, type of music, type of emotion, decision-making tasks, and study results. The included studies aimed to investigate the effects of music on prosociality and aggression, risk-taking, and other decision-making processes. All studies used experimental designs and most of them used pre-selected music and stimulation through music listening. Different decision-making tasks were used, such as a gambling task, helping behavior tasks, and even assessment of aggressive behavior through adding hot chili sauce to food. Results showed that music is a powerful and engaging stimulus that influences decision-making processes and risk-taking, promotes prosociality, and affects customers’ behavioral choices. Different underlying processes in the interaction between music, mood, and decision-making are discussed. This review contributes to promoting research on the use of background music as an arousal and mood inducer in different contexts, as well as music-based interventions to foster prosociality and decrease aggressive behaviors.
Decision-making can be defined as “the process of choosing a preferred option or course of action from among a set of alternatives” (Kitajima & Toyota, 2013; Shafir, 1999, p. 220). Throughout history, theories have attempted to explain decision-making in terms of a strict, normative mode of rationality (Loewenstein & Lerner, 2003). Such theories usually implied a decision-maker capable of boundless rationality and ideal sensitivity to information. Tversky and Kahneman (1974), however, have demonstrated effects of variations in information presentation on judgment and decision-making. Since then, researchers have investigated other possible variables interfering in decision-making. These newer models stress the importance of describing how real decision-making actors behave and which factors influence their decisions. Hypotheses involving variables such as emotions (Zheng, Yang, Jin, Qi, & Liu, 2017), social or moral implications (Greene, Nystrom, Engell, Darley, & Cohen, 2004; Zinchenko & Arsalidou, 2018), and pecuniary motivation (Brockmeyer, Simon, Becker, & Friederich, 2017) have been thoroughly explored in the last decades.
Current theories agree that human decisions cannot be explained only by rational imperatives and that decision-making is fundamentally supported by emotions (Frank, Cohen, & Sanfey, 2009; Loewenstein, 1996; Phelps, 2009; Sokol-Hessner, Camerer, & Phelps, 2013). Despite the healthy diversity of theories (Damasio, 1994, 1996; Damasio, Tranel, & Damasio, 1991; Hansen, 2005; Hansen & Christensen, 2007; Loewenstein, Weber, Hsee, & Welch, 2001), all focus on understanding how, when, where, and to what extent emotion is related to decision-making. Hence, current experimental studies control the emotion of participants when investigating a decision-making process.
According to Russell’s (1980) circumplex model, emotions vary in a two-dimensional space, with one dimension corresponding to arousal (or activation) and the other to mood (or valence). Arousal refers to the physical and psychological activation of an emotion, while valence is related to a pleasure–displeasure continuum (Posner, Russell, & Peterson, 2005). According to this model, specific emotions “arise out of patterns of activation within these two neurophysiological systems, together with cognitive interpretations and labeling of these core physiological experiences” (Posner et al., 2005, p. 716). However, it is important not to reduce all affective states to these two dimensions, since “individuals do not experience, or recognize, emotions as isolated, discrete entities, but they rather recognize emotions as ambiguous and overlapping experiences” (Posner et al., 2005, p. 719).
From the many different variables that may influence emotional states, music has shown robust effects (Coan & Allen, 2007), because it can influence the research setting even without the conscious attention of participants to the stimulus, thus representing real-life situations (Halko, Mäkelä, Nummenmaa, Hlushchuk, & Schürmann, 2015). Moreover, music is ubiquitous, since musicality is a universal and cross-cultural characteristic of humankind, deeply connected to its social and cultural context (Trehub, Becker, & Morley, 2015). Musical abilities develop very early in infants’ development and are very sophisticated even in non-musicians. Music listening and music making involve complex cognitive processes that are shared with the processing of language, suggesting that musicality is a natural skill of the human brain (Koelsch, 2011).
Neuroimaging evidence has shown that music activates a network comprising amygdala, hippocampus, parahippocampal gyrus, hypothalamus, insula, cingulate cortex, orbitofrontal cortex, and temporal poles, which is involved in the modulation of emotions (Koelsch, 2009, 2014). Moreover, listening to pleasurable music activates the nucleus accumbens and the dopaminergic reward system (Blood & Zatorre, 2001; Koelsch, 2009, 2014). It is impossible to find an inter-cultural definition of music (Trehub et al., 2015). Thus, for this review we opted for a broad definition of music as temporally structured human activities, social and individual, in the production and perception of sound organized in patterns that convey non-linguistic meaning (Merriam-Webster, n.d.).
Emotional responses to music have been studied through subjective, behavioral, and physiological measures, corresponding to different brain networks and different levels of cognitive processes (Koelsch, 2015). At the level of the brain stem, music can modulate the arousal component of emotion, through changes in physiological responses, and elicit motor reactions, such as a smile. Such responses are related to automatic and noncognitive processes. At the level of the neocortex, music is responsible for more cognitive and conscious processes, involving subjective feelings, as well as voluntary actions and behaviors, such as singing or foot tapping (Koelsch, 2014, 2015).
Besides the properties of music, factors such as musical preferences and competences, personality traits, the stimulus selection, participants’ involvement in the music, the social or solitary setting, as well as the quality of the performance have been shown to make important contributions to emotional reactions to music (Dunbar, Kaskatis, MacDonald, & Barra, 2012; Liljeström, Juslin, & Västfjäll, 2012; Koelsch, 2015). Music-based interventions and musical training have also been shown to improve cognition, language, attention, memory, and executive functions (Fusar-Poli, Bieleninik, Brondino, Chen, & Gold, 2017; Koelsch, 2009, 2011; Sachs, Kaplan, Der Sarkissian, & Habibi, 2017; Zumbansen, Peretz, & Hébert, 2014). Nevertheless, the effects of music in the decision-making process have been less investigated. Additionally, we did not find previous reviews about the music effects on decision-making.
Therefore, this qualitative systematic review aimed to examine music-induced emotion effects on decision-making. In particular, we wanted to investigate how music elicits the arousal and mood dimensions of emotion, thereby influencing the decision-making process. Qualitative systematic reviews allow a comprehensive understanding of the process of interventions and studies, rather than focus on their effectiveness (Stern, Jordan, & McArthur, 2014), and they generally organize data into categories and themes (Butler, Hall, & Copnell, 2016). We analyzed the included articles according to the following categories: aims of the study, participants, study design, type of music, type of emotion, decision-making tasks, and study results.
Method
In undertaking this review, we followed the criteria of the PRISMA checklist (Moher, Liberati, Tetzlaff, Altman, & The PRISMA Group, 2009; see Figure 1 for a summary). Initially, a preliminary search was performed in the electronic databases PubMed and PsycInfo in order to identify the more appropriate keywords. The first two authors independently screened PubMed and PsycInfo in September 2016 using the following terms: “music” AND “decision making”; “music” AND “decision making” AND “mood”; “music” AND “decision making” AND “emotion”; “sound” AND “decision making” AND “emotion”; and, “sound” AND “decision making” AND “mood.” Searching was restricted to articles published in the last ten years (2006–2016). All relevant records were extracted to Zotero 4.0 reference management software (Roy Rosenzweig Center for History and New Media). Studies were included if they met the following criteria: empirical articles published in English and involving human participants; music considered as a temporally structured human activity, involving and integrating rhythm, melody, harmony, and lyrics (Merriam-Webster, n.d.); emotion considered both as the arousal and the mood dimension (Russell, 1980); decision-making considered as “the process of choosing a preferred option or course of action from among a set of alternatives” (Shafir, 1999). Every included article had its references screened. Data searching, screening and selection were undertaken by two independent reviewers. Disagreements were resolved through discussion with the third author. All included articles were entirely read and examined focusing on their main characteristics and the similarities and differences between them.

Flow of studies through the review process.
Results
From the database searching, 634 records were identified. After removing duplicates, we obtained 508 articles and screened their titles and abstracts. Theses, dissertations, book chapters, articles in languages other than English, and irrelevant records were excluded. According to the eligibility criteria abovementioned, eight studies were included. Subsequently, all the references of these eight articles were screened and eight other articles were included, identifying a total of 16 articles. After the full-text analysis, one article was excluded for being a duplicate study of another article. In the end, 15 articles were included in this review and analyzed according to the following categories: aims of the study, participants, study design, type of music, type of emotion, decision-making tasks, and study results. Table 1 presents these categories.
Included studies characterized according to the analyzed categories.
Participants
Regarding participants, almost all of the included studies involved healthy people and just one of them investigated schizophrenia patients (Moritz et al., 2009). Most of the studies involved students (Brooks & Schweitzer, 2011; Day et al., 2009; Fischer & Greitemeyer, 2006; Greitemeyer, 2009a, 2009b; Skulmowski et al., 2014; Strick et al., 2015), while one of them investigated adolescents and teenagers (Halko & Kaustia, 2012) and just one of them included children (Kirschner & Tomasello, 2010). In general, the number of participants was quite small, with five studies having less than 40 participants (Chung et al., 2016; Day et al., 2009; Greitemeyer, 2009b, Study 1; Halko & Kaustia, 2012; Halko et al., 2015), and seven studies with 40 to 60 participants (Greitemeyer, 2009b, Study 2, 3 and 4; Greitemeyer, 2011, Study 5; Moritz et al., 2009; Schulreich et al., 2014). Five studies included 60 to 100 people (Greitemeyer, 2009a; Kirschner & Tomasello, 2010; Kniffin et al., 2016, Study 1; 1 Skulmowski et al., 2014; Strick et al., 2015, Study 1), while four of them involved more than 100 participants (Brooks & Schweitzer, 2011; Fischer & Greitemeyer, 2006, Study 1 and 3; Kniffin et al., 2016, Study 2).
Study design
All of the analyzed studies used an experimental design. In particular, some of them used between-subjects designs (Brooks & Schweitzer, 2011, Study 1; Chung et al., 2016; Fischer & Greitemeyer, 2006, Study 1 and 3; Kirschner & Tomasello, 2010; Kniffin et al., 2016, Study 1 and 2; Strick et al., 2015, Study 1). Four studies used within-subjects designs (Day et al., 2009; Halko & Kaustia, 2012; Halko et al., 2015; Schulreich et al., 2014), while two studies combined both between and within-subject factors (Moritz et al., 2009; Skulmowski et al., 2014).
Type of music
In terms of the type of music, we highlight that the vast majority of the studies used standardized songs for all the participants, pre-selected by experts or experimenters. Only the research of Halko and colleagues used liked and disliked music, previously selected by participants (Halko & Kaustia, 2012; Halko et al., 2015).
Nevertheless, almost all the studies that used pre-selected music justified the musical selection and assessed the music-mood congruence through different strategies. Some research carried out pilot studies to pretest the music (Brooks & Schweitzer, 2011, Study 1; Fischer & Greitemeyer, 2006; Greitemeyer, 2009a, Study 3, 2009b, Study 1, 2, 3 and 4, 2011, Study 5; Kniffin et al., 2016; Strick et al., 2015, Study 1), others used musical excerpts identified from previous studies (Chung et al., 2016; Schulreich et al., 2014; Skulmowski et al., 2014), while in Moritz and colleagues’ study (2009) the music–mood congruence was tested by experts (psychologists). Moreover, Day et al. (2009) controlled the ecological validity of the music, selecting a popular style, more accepted by office workers, than classical music which is more commonly used in research.
Almost all of the studies used music listening or background music, except for Kirschner and Tomasello (2010), who used live music making with background music. Regarding the characteristics of the musical stimuli, some studies specifically used vocal music (Fischer & Greitemeyer, 2006; Greitemeyer, 2009a, Study 3, 2009b, Study 1, 2, 3 and 4, 2011, Study 5; Kniffin et al., 2016, Study 1 and 2), while others used instrumental music (Brooks & Schweitzer, 2011, Study 1; Day et al., 2009; Moritz et al., 2009; Schulreich et al., 2014).
Regarding music styles, among the studies that used pre-selected music, Brooks and Schweitzer (2011, Study 1) and Chung et al. (2016) used both classical and popular music. Some studies used popular music, such as New Age Style, German songs, house music, rock and heavy metal (Day et al., 2009; Fischer & Greitemeyer, 2006, Study 1 and 3; Greitemeyer, 2009a, Study 3, 2009b, Study 1, 2, 3 and 4, 2011, Study 5; Kniffin et al., 2016; Moritz et al., 2009; Strick et al., 2015, Study 1). Moreover, Schulreich et al. (2014) selected music from various epochs and styles (classical music, Irish jigs, jazz, reggae, South American and Balkan music), while Kirschner and Tomasello (2010) used children’s music and Brooks and Schweitzer (2011, Study 1) and Skulmowski et al. (2014) selected music from soundtracks.
Some studies specified that music was used to elicit a particular mood or emotion, while others were interested in the effects of some particular musical or non-musical elements of the songs, such as music tempo (faster versus slower background music; Day et al., 2009) or the lyrics. In particular, the research group of Greitemeyer and colleagues investigated the effects of music with misogynous and man-hating content (Fischer & Greitemeyer, 2006, Study 1 and 3) and with prosocial versus neutral lyrics (Greitemeyer, 2009a, Study 3, 2009b, Study 1, 2, 3 and 4, 2011, Study 5). In particular, Fischer and Greitemeyer (2006, Study 1 and 3) matched all the songs according to music style, artist, level of aggression, negativity, and arousal level, and they used songs from different artists in their experiments. This allowed them to control that the effects of the music in the aggressive behavior were primarily attributed to the misogynous, man-hating, or neutral lyrics. Similarly, Greitemeyer (2009a, Study 3) controlled for the mood and the arousal dimension of songs, Greitemeyer (2009b, Study 1, 2, 3 and 4) controlled for mood and Greitemeyer (2011, Study 5) controlled for mood, arousal, as well as for the perceived aggressive content.
Type of emotion
Not all reviewed studies directly referred to an underlying emotion elicited by music and related to a decision-making process. Nevertheless, each of them investigated emotion either as an independent variable, elicited by music, or as a covariable, having a mediator effect between music and decision-making process.
For example, some studies directly investigated emotion or mood as an independent variable, assuming that music affects decision-making and behavior through mood modulation. Using Russell’s (1980) circumplex model of emotions, we can distinguish studies that were interested in the music-induced mood (or valence) effects on decision-making by investigating anxiety (Brooks & Schweitzer, 2011, Study 1), anxiety and happiness (Moritz et al., 2009), happiness and unhappiness (Schulreich et al., 2014), pleasant and unpleasant mood (Chung et al., 2016), or negatively valenced emotions (Skulmowski et al., 2014). Only Day et al. (2009) were interested just in the arousal or activation dimension (Russell, 1980), investigating the effects of tempo on decision-making, while Skulmowski et al. (2014) investigated both dimensions of emotion, the music-induced arousal and a negative valence.
Additionally, Strick et al. (2015) were interested in the effects of music on psychological transportation, which occurs when people are involved in a story or an experience and they “lose” temporarily the real world (Green & Brock, 2000). Transportation is a psychological concept which can be considered similar to arousal, because it is independent of the valence of emotion. Strick et al. (2015) also investigated the positive and negative affective response, which can be related to the mood or valence dimension of Russell’s (1980) model. The studies of Halko and colleagues, despite not being interested in specific emotions, assumed that mood has a mediator effect between music and risk-taking (Halko & Kaustia, 2012; Halko et al., 2015).
Other studies did not assume emotion as a mediator between music and decision-making and were interested in specific behavioral variables, such as aggressive behavior (Fischer & Greitemeyer, 2006; Greitemeyer, 2011) and prosocial behavior, defined by the authors as helping and cooperative behavior derived from social commitment and bonding (Greitemeyer, 2009a, 2009b, Study 1, 2, 3 and 4; Kirschner & Tomasello, 2010). Greitemeyer (2009b) controlled for mood in Study 1, while Kirschner and Tomasello (2010) discussed that the effects of music on prosocial behavior might be attributed to the positive mood induced by music. Kniffin et al. (2016) investigated the effects of music on happiness and unhappiness (Study 1), and on pleasant and unpleasant mood (Study 2). They controlled for mood and found that music effects might be both direct and indirect (mediated by mood).
To end, many studies assessed mood and emotion through Likert scales and questionnaires: the Positive and Negative Affect Schedule (PANAS; Watson et al., 1988; Chung et al., 2016; Greitemeyer, 2009a, Study 3, 2009b, Study 1, 2, 3 and 4); the four-item mood short form (Peterson & Sauber, 1983; Kniffin et al., 2016, Study 1 and 2); the Perceived Arousal Scale (Anderson et al., 1995; Greitemeyer, 2009a, Study 3, 2011, Study 5); and the State Hostility Scale (Anderson et al., 1995; Greitemeyer, 2011).
Decision-making tasks
All studies analyzed decision-making quantitatively. Despite the many different tasks, it was possible to group some of them according to a common characteristic: adding hot chili sauce, gambling, and helping someone.
Fischer and Greitemeyer (2006), in Study 1, and Greitemeyer (2011), in Study 5, used a similar decision-making task that consisted of putting hot chili sauce into a cup for another participant to consume in another experiment. The only difference between them was that Fischer and Greitemeyer (2006) presented the person (who was going to consume the sauce) before the task. In both studies the quantity of sauce grams put into the cup was considered the measure of aggression.
Halko and Kaustia (2012) and Halko et al. (2015) used almost the same gambling task, in which participants should accept or reject gambles that offered a 50% chance of gaining money. At the beginning of the task, the gain and loss amount were shown to the participants. Subsequently, they had to make the decision of accepting or rejecting the offer. The next gamble was presented, without providing the participant with the result of the last one.
Helping someone includes tasks involving: donating, picking up objects, or being willing to help. Greitemeyer (2009a), in Study 3, Strick et al. (2015), in Study 1, and Greitemeyer (2009b), in Study 3, used a donation decision-making task. In Greitemeyer (2009a) the task involved actual donating behavior, while Strick et al. (2015) and Greitemeyer (2009b) measured only donating behavior intentions. The donation question of Greitemeyer (2009b) was not just about money, but included options such as “have the kids come live with you until a permanent home was found” (Greitemeyer, 2009b, p. 1505).
During the experiment session of Kirschner and Tomasello (2010) and Greitemeyer (2009b, Study 1), the participant is faced with the opportunity to help another person: the researcher (Greitemeyer, 2009b) or another participant (Kirschner & Tomasello, 2010). Both studies used the number of dropped objects the participant decided to pick up from the floor as a measure of prosocial behavior. Moreover, Kirschner and Tomasello (2010) also considered the effort made by the participant as a variable. Greitemeyer (2009b) designed a scene where the researcher always asked for help, while in Kirschner and Tomasello (2010) the children involved in the “accident” were not aware of what was happening.
Greitemeyer (2009b), in Study 2, used a decision-making task involving the willingness to help others. After the main task, the participants were told the experiment was over. Subsequently, a different researcher entered the room asking for help in another research not involving any compensation, and participants had to indicate their willingness to take part and how much time they could give.
The other studies used heterogeneous decision-making tasks. Brooks and Schweitzer (2011) used a decision-making task where participants had to negotiate price, warranty period, and service period of a cell-phone shipment. In Day and colleagues’ study (2009) participants had to apply previously learned decision strategies to choose one protection lotion brand and four equivalent versions. In Moritz et al. (2009) participants were presented with paintings and possible titles. They could decide to connect a painting to a title or opt not to answer. In the study of Fischer and Greitemeyer (2006) participants were told the experiment was over and were asked to help in another experiment deciding for how long two subsequent participants should keep their hands in ice water.
Several experiments used famous decision-making tasks. Greitemeyer (2009b) used the dictator game, where participants have to decide how much money they want to give to a receiver. Chung et al. (2016) used the ultimatum game (Güth, Schmittberger, & Schwarze, 1982), where a proposer decides how to split a resource between themselves and a responder, who chooses whether to accept or reject the division. The proposal is implemented only if the responder accepts.
The Voluntary Contribution Mechanism (VCM), used by Kniffin et al. (2016), is a traditional public goods experiment about resource allocation (Isaac & Walker, 1988) that incentivizes and rewards cooperation. The participant has to decide how to allocate resources between an individual exchange (private good) and a group exchange (public good).
Schulreich et al. (2014) used the Random Lottery Pairs, where the participant is presented to an array of binary lottery choices and picks one of the lotteries in each pair, facing multiple pairs in sequence. In Schulreich et al. (2014) the two possible payoffs were strictly positive, limiting the experiment to the gain domain, differing from each other only in riskiness. It was expected that participants would make the riskier or the less risky decision. To end, Skulmowski et al. (2014) used the trolley dilemma, which consists of a scenario where a railway trolley is out of control and will run a number of people down. The participant chooses between sacrificing one person to save these people or letting them die.
Study results
Prosociality and aggression
Our review found several significant effects of music on decision-making tasks involving prosocial, cooperative, and aggressive behavior. In particular, Greitemeyer (2009a, Study 3) showed that music affected prosocial behavior, since participants who had listened to prosocial songs were more likely to donate money than participants in the neutral songs condition.
Similarly, in another article, Greitemeyer (2009b, Study 1, 2, 3 and 4) showed that listening to prosocial songs, compared to neutral music, promoted prosocial and cooperative behavior, since participants helped to pick up more dropped pencils (Study 1), reported a greater willingness to devote more time in further studies (Study 2) and to help in a hypothetical decision-making task (Study 3), and showed more cooperative behavior in the dictator game (Study 4). When controlling for positive and negative mood, the effect of type of song on prosocial behavior remained evident, suggesting that different mood states are unlikely to account for the effect of listening to prosocial songs on helping behavior. Conversely, in Study 4 empathy has been shown to mediate between music and cooperative behavior.
Similarly, Greitemeyer (2011, Study 5) showed that prosocial music not only increased prosocial and cooperative behavior, but also decreased aggression. In this study, participants in the prosocial music condition administered less hot chili sauce than did participants in the neutral music condition. Moreover, the significant effect of the music condition was reduced to non-significance when controlling for state hostility, suggesting that the effect of listening to prosocial music on aggressive behavior is mediated by differences in the reported aggressive affect.
Fischer and Greitemeyer (2006) showed that misogynous and man-hating song lyrics increased aggressive behavior in both men and women. Study 1 used the administration of hot chili sauce as a decision-making task to investigate aggressive behavior, while in Study 3 participants were asked to assign the time for two subsequent participants to keep their hands in ice water. Both studies showed that listening to misogynous and man-hating music increased the aggression toward the opposite sex.
Similarly, Kirschner and Tomasello (2010) showed that, after joint music making, children of both genders helped one another more than children in the no-music condition. Interestingly, children in the music condition that did not help offered verbal excuses more frequently than children in the no-music condition, suggesting that music fosters empathy and social commitment. Kniffin et al. (2016, Studies 1 and 2) selected as stimuli a set of happy and unhappy songs, that had been previously tested. Results showed that listening to happy music, compared both to unhappy music and no-music, increased cooperation, since participants in the happy music condition generated higher economic contributions to the public group. Differently from Greitemeyer (2009b, Studies 1, 2, 3 and 4), Kniffin et al. (2016, Study 2) suggested that happy music has both direct and indirect (mediated by mood) effects.
Instead of investigating happy and unhappy music, Strick et al. (2015, Study 1) were interested in the effects of moving and non-moving music on behavioral intentions in the context of video ads. Results showed that participants listening to moving music reported more willingness to donate money and to forward the film clip to five friends. As the authors hypothesized, moving music elicited a highly emotional transportation into the narrative of the video ad, therefore increasing participants’ cooperation and helping behavior by temporarily suppressing their tendency to consider the manipulative intent of the advertiser.
Differently from all the aforementioned studies, Skulmowski et al. (2014) did not find differences between the anxious music and the silent condition in the proportion of sacrificed single persons in a modified version of the trolley dilemma. Nevertheless, they found a significant difference in the score of negative emotions (“annoyed,” “angry,” “irritated,” and “gross”), indicating a stronger negatively valenced mood in the group that listened to music. Moreover, the eye tracking 2 results showed that the irritating music increased participants’ arousal. Contrary to the hypothesis of the study, music did not appear to affect moral decisions.
Risk-taking
Articles studying risk-taking (Halko & Kaustia, 2012; Halko et al., 2015; Schulreich et al., 2014) have all found correlations between emotion and risk-taking. Halko and Kaustia (2012) verified the impact of music on the tendency to participate in gambles, concluding that liked music alleviates loss aversion, while disliked music exacerbates it. The mean effects of liked and disliked music, compared to no music, are statistically significant. Liked music increased loss amount, while disliked music reduced it. Interestingly, the reduction caused by disliked music was more intense than the increase of loss amount provoked by liked music. The effect varied, however, for different types of gambles.
Halko et al. (2015) used functional MRI to analyze the brain mechanisms underlying music-induced unstable risk preferences. They gathered evidence that subjectively preferred music increases financial risk-taking and reduces loss aversion. When liked music was played, mean valence was significantly higher and arousal significantly lower compared to disliked music. The frequency for accepting a gamble grew in this order: disliked music, no music, and liked music. The disliked music, however, had no significant effect on gamble acceptance. Losses were weighed approximately twice as much as gains. Behavioral loss aversion, when calculated separately for liked music and disliked music, was significantly reduced in the liked music.
In Schulreich et al. (2014) music altered the emotional state of happiness in a different manner and this effect was diminished over time. While happy music was associated with greater happiness, sad music and random tone sequences were associated with lower happiness. The changes in participants’ choices were explained through the changes in how they convert objective probabilities into subjective decision weights. The affective nature of this link was corroborated by the results, showing that in the happy condition the decision weights associated with the larger payoffs were higher than in the sad and in the random tone conditions. In the happy condition participants chose more the riskier lottery compared to the “sad” condition. Combined, these findings suggest that subjectively liked music and happy music increase risk-taking, while disliked music and sad music decrease it.
Other decision-making processes
By comparing healthy controls with schizophrenia patients, Moritz et al. (2009) found that schizophrenia patients with current delusions made a higher number of decisions under the anxiety-induction condition, compared to non-deluded patients and healthy subjects.
Day et al. (2009) analyzed the differences between two different tasks (in terms of difficulty) and between two different music tempos. The independent variables were different dimensions of decision-making processes: decision accuracy, decision time, search pattern, percentage of information searched, reacquisition rate, and speed of information processing. Significant differences were found for accuracy and search pattern. Faster tempo condition presented higher accuracy, suggesting that participants in this group solved more correctly the decision problem. Moreover, faster tempo condition showed a lower search pattern, which is “used to reflect whether a subject’s information search direction tends to be attribute-based (intra-dimensional) or alternative-based (inter-dimensional)” (Day et al., 2009, p. 141). Participants who listened to faster music used more intra-dimensional search to solve the problem, compared to participants in the slower tempo condition. This suggests that faster music allows attribute-based processing, where “the values of several alternatives on a single attribute are processed before information about a second attribute is processed” (Day et al., 2009, p. 138). An interaction between music tempo and task difficulty was found for search pattern, showing that only for a WADD task there was a significant effect, where faster tempo presented a lower search pattern. A significant interaction effect of music tempo and task difficulty was found for only one of the tasks (EBA), where the reacquisition rate was significantly lower with the presence of the faster tempo.
Chung et al. (2016) induced pleasant and unpleasant moods, using musical excerpts that had been selected in a previous study. Participants were assigned either to a pleasant group, which listened to pleasant music, or an unpleasant group, which listened to unpleasant excerpts. Results showed that the unpleasant group reported increased negative affect after mood induction relative to pre-induction, while the pleasant group reported marginally decreased negative affect. A significant interaction between time and group was found for positive affect scores, suggesting that the less favorable the offers were, the more participants rejected them. A significant interaction was also found between offer and group, revealing that the unpleasant group rejected unfair offers more often than the pleasant group. Rejection rates of unfair offers were negatively correlated with felt fairness and felt happiness in the unpleasant group, indicating that the unpleasant group rejected more often, as they perceived the offer to be less fair and were less happy. The pleasant group also showed a negative correlation between felt happiness and rejection rates.
Brooks and Schweitzer (2011) have compared an independent variables emotion condition (anxiety or neutral) and role (buyer or seller) with dependent variables such as aspirations, expectations, first offers, exit decisions, and individual outcomes. Emotion showed a significant effect on expectations. Participants in the anxious music condition expected to earn less than participants in the non-anxious music group. Considering the first offers, participants in the anxious music condition made significantly lower first offers than participants in the non-anxious music condition. With regard to the individual outcomes, the analyses showed that participants in the anxious music group earned less profit than participants in the non-anxious music condition, as well as that participants who were paired with an anxious counterpart earned significantly more profit than participants who were paired with a non-anxious counterpart.
Discussion
This qualitative systematic review aimed to examine the music-induced emotion effects on decision-making. Our results showed that music affects the decision-making process, influences risk-taking and promotes prosociality. Music is a complex and powerful stimulus in people’s daily life and several factors may contribute to the emotional or behavioral responses to music: the musical properties of the stimulus, participants’ individual characteristics, and contextual factors (Liljeström et al., 2012).The majority of the studies did not take into account participants’ musical preferences. Nevertheless, there is a general consensus that both properties of musical stimulus and individual differences contribute significantly to the induction of musical emotion (Kreutz, Ott, Teichmann, Osawa, & Vaitl, 2008; Liljeström et al., 2012; Trehub et al., 2015). In particular, Liljeström et al. (2012) showed that self-chosen music aroused more intense and more positive emotions than randomly sampled music. Future research must consider participants’ musical preferences in order to increase their ecological validity.
Evidence has shown that making music induces more positive affect than music listening (Dunbar et al., 2012). Nevertheless, just Kirschner and Tomasello (2010) used live music making. An active involvement in music, as in singing, dancing, and drumming, promotes more endorphin release and elicits more positive affect, while simply listening to music does not induce the same effects (Dunbar et al., 2012). Kirschner and Tomasello (2010) found that joint music making has positive effect on prosociality, supporting the evolutionary hypothesis of the origin of music, which suggests that it allows the creation and maintaining of social bonds and prosocial commitment among social groups. Interestingly, almost all the studies that investigated the music effects on prosocial or aggressive behavior used vocal music instead of instrumental. This is in line with research that shows that singing is particularly powerful in fostering caregiver–infant bonding (Trehub et al., 2015), suggesting that vocal music may be more efficient in promoting prosocial and cooperative behaviors. Similarly, a recent study by Weinstein, Launay, Pearce, Dunbar, and Stewart (2016) showed that singing, in both small and large groups, increases positive affect, feelings of inclusion and social connection, and causes elevated pain thresholds, generally associated to a higher endorphin release. These effects are greater in larger groups than in smaller and more familiar groups, suggesting that music making is particularly effective in fostering social connections between large groups of unfamiliar individuals. Future studies might compare the use of vocal and instrumental music in decision-making processes that involve aggressive and prosocial behavior.
We did not find homogeneity in decision-making tasks, probably due to the different theoretical background of the included articles. The Iowa Gambling Task, for example, is a risk-taking decision-making task, commonly used to investigate the role of emotion in decision-making processes (Reimann & Bechara, 2010), but none of the included studies employed it. Some studies have focused on decision-making processes that involve a long deliberation and many steps to be followed (for example, Day et al., 2009), while others have used almost automatic responses as decision-making tasks (for example, Greitemeyer, 2011; Kirschner & Tomasello, 2010).
The studies highlighted explications for the interaction or the mediator factors between music and decision-making. For example, Day et al. (2009) investigated the mediation of attention, by comparing the two different perspectives of music as a distractor or as an arousal inducer. According to Kahneman’s capacity model (Kahneman, 1973), background music might be a distractor, because it demands cognitive capacity and reduces the mental resource available for the cognitive task, thus impairing the decision-making process. On the contrary, music might be an arousal inducer and might increase listeners’ mental resource, thus promoting decision-making. The results of the studies supported the arousal effect of music.
One of the most investigated mediator factors between music and decision-making is mood. While many studies supported the mood induction effect of music, others challenged it. Studies that investigated prosociality showed that neither cognition or mood can explain the interaction between music and decision-making process. On the contrary, specific prosocial feelings like interpersonal empathy were elicited by prosocial songs and promoted prosocial behavior. Results were in line with the General Aggression Model (GAM; Bushman & Anderson, 2002) and the General Learning Model (GLM; Buckley & Anderson, 2006). The GAM suggests that violent media may affect aggressive ideas, by evoking associations to aggressive cognitions, arousal, and affect related to violence. The GLM suggests that exposure to media may affect a person’s cognition, affect and arousal, thus affecting their behavior.
Nevertheless, both models were only partially supported, because the effects of music exposure on social behavior were mediated more by the affective route than the cognitive route, which is more commonly activated by video games. Combining these findings, we suggest that music affects both directly and indirectly (with the mediation of mood, emotion, and affection) the decision-making process, while the cognitive route seems to have a smaller influence. Nevertheless, as a limitation of these studies we highlight that the effects of music on prosociality may be partially affected by the prosocial content of the lyrics. The aforementioned study by Weinstein et al. (2016) also investigated the effects of music on prosociality. Even if the music used in this study had lyrics, it did not have prosocial content and researchers were interested in the effects of music making, rather than the effects of music per se. This research also highlighted the relationship between music and mood, showing that singing increased positive affect, feelings of inclusion, and social connection. Future research might investigate separately the effects of prosocial music without the lyrics, prosocial song lyrics without the music, and the interaction of both.
With regards to risk-taking, the included studies confirmed the current literature (Reimann & Bechara, 2010; Guillaume et al., 2009) by showing that emotion interferes in decision-making. For the other articles not related to risk-taking or prosocial behavior, music was also an effective arousal or mood inducer. Nevertheless, we highlight that some studies did not find significant effects in all the investigated conditions. For example, Moritz et al. (2009) only found significant effect when they split the patient group for delusion to find an interaction between music and group. Another example is in Brooks and Schweitzer’s study (2011), where no significant effect of emotion (anxious vs. neutral) was found on aspiration, and no interaction effect of the negotiator’s emotion and the counterpart’s emotion on individual outcomes.
Despite these non-significant or inconclusive results, most of the studies showed that music is effective in eliciting arousal or mood variability in different kind of tasks and in affective decision-making. This variability of tasks supports a consistency of the effect, and provides a rationale for the use of music as an arousal and mood inducer in different areas of research. However, our findings showed that music is still not so widespread as one might expect in the research involving decision-making. Interestingly, six of the articles included in this review are part of a line of studies made by two groups of researchers and their colleagues. This shows that, once music is used in the experiments and it shows positive outcomes to the research field, researchers are motivated to continue their investigation with this stimulus, to provide other evidence and improve the theory.
To end, this review allows a reflection about the necessity of environmental control during any kind of experiment, in order to guarantee the internal validity of research. Our results showed that music might be an effective intervenient variable over emotion, interfering in research results. Generalizing our findings, even experiments that do not investigate music must take into account and control the emotional and behavioral effects of musical and acoustic stimuli (e.g. the presence of music or noise in the acoustic background before or during the experimental setting). Finally, this review provides a rationale for the use of music-based interventions to foster prosocial and cooperative behavior and decrease aggression.
Footnotes
Funding
The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This publication was supported by the Brazilian foundation “Comissão de Aperfeiçoamento de Pessoal de Nível Superior” (CAPES).
