Music with certain levels of bass makes people feel more powerful, according to a Northwestern University study.

Previous studies have showed that music has positive effects on people including enhancing learning and motivation, and reducing physical pain.

However, no study until now has focused on the relationship between music and sense of power. Through the study, the researchers wanted to determine whether music can transform the psychological state of the listeners.

"When watching major sports events, my coauthors and I frequently noticed athletes with their earphones on while entering the stadium and in the locker room," said Dennis Hsu of the Kellogg School of Management, in a press release. "The ways these athletes immerse themselves in the music - some with their eyes steely shut and some gently nodded along the beats - seem as if the music is mentally preparing and toughening them up for the competition about to occur."

For the study, the researchers first pre-tested 31 pieces of music from several genres like sports, music, hip-hop and reggae to see how powerful participants felt listening to the 30-second clips. From this pre-test, they identified highest power and lowest power songs.

Songs rated as powerful included Queen's "We Will Rock You" and 2 Unlimited's "Get Ready for This", while songs rated lower included Fatboy Slim's "Because We Can" and Baha Men's "Who Let the Dogs Out".

Then, in a series of experiments, the researchers looked at how the highest and lowest rated power songs affected both people's sense of power and three psychological and behavioral consequences of power: thought abstraction, illusion of control and the desire to excel in competitive interactions.

To measure illusion of control, they conducted die-rolling task, an item categorization task to measure abstraction and a decision-making scenario to measure moving first. "Part of our objective was to test whether music produces the same downstream effects of power found in other sources," Hsu said.

The participants were also surveyed about their positive feelings.

The researchers found that the high-power music not only triggered a sense of power unconsciously, but also evoked the three consequences of power.

"Because participants did not report increased powerful feelings after reading the lyrics, we can rule out the semantic priming effect of lyrics in the selected songs," Hsu explained.

The researchers also looked at one component of music to explain the music-power effect: bass levels. Bass sound and voice are frequently utilized in popular cultures to project perceptions of dominance and confidence. For example: James Earl Jones as Darth Vader in Star Wars.

"We chose to manipulate bass levels in music because existing literature suggests that bass sound and voice are associated with dominance," Hsu said.

In bass experiments, the researchers asked participants to listen to novel instrumental music pieces with variable bass levels. In one experiment, they surveyed participants about their self-reported feelings of power and in another they asked them to perform a word-completion task designed to test implicit or unconscious feelings of power.

The researchers found that heavy bass was directly proportional to greater feelings of power. Participants listening to heavy bass fared well in the implicit task as compared to those listening to low bass music.

The effect of bass levels explains the "contagion hypothesis" - when people hear specific music components that express a sense of power, they imitate these feelings internally. For example "We Are the Champions" is often played to celebrate victory.

"Importantly, because we used novel, never-before-heard music pieces in these experiments, it suggests that the effect may sometimes arise purely out of contagion," Hsu said. "Of course, this does not preclude the possibility that music could induce a sense of power through other processes, such as conditioning."

The finding is published in the journal Social Psychological and Personality Science.