Voice pitch and personality traits

A new science fiction massive multiplayer online role-playing game (MMORPG) was released that allows players to design the sound of their avatar’s voice. The game features a sliding pitch scale for players to select the fundamental pitch (f0) and formant frequencies (pf) (both measured in hertz) of their avatar’s voice. As players engage with the game world and interact with other players through their avatar, specific personality traits for their avatar would emerge. In order to determine whether the avatars created within this science fiction game world resemble the vocal and personality patterns found in the real-world, the designers of the game collaborated with psychologists to investigate this comparison. The game designers were particularly inspired by Stern et al. (2021)’s study that explored how voice pitch is related to self-reported extraversion, dominance, and sociosexuality in men and women.

The current video game study recruited a sample of 475 players from the game, 200 men and 275 women, all aged from 20 to 45. In Stern et al. (2021)’s study, participants would read short text passages so that the researchers could determine the fundamental pitch and formant frequencies of the participants’ voice. However, the game designers are able to extract the information about an avatar’s voice from the selections that the player made on the sliding pitch scale when the player created their avatar. The game designers asked the 475 players to each fill out a questionnaire about their avatar’s personality traits (Likert ratings on a scale from 1-5 from the Big 5), dominance (Likert ratings on a scale from 1-5 from the Interpersonal Adjective List, and sociosexuality (Likert ratings on a scale from 1-5 from the SOI-R). The sociosexuality score is the mean of the ratings for the three dimensions of sociosexuality: behaviour, attitude, and desire. The game designers have already calculated the Cronbach’s alpha for the raw scores of the scales and found that there was good reliability. As certain MMORPGS can provide the potential for players to explore and express their sexuality through their avatars, such as the current new science fiction MMORPG that is the focus of this scenario, the game designers are curious as to whether there is a relationship between these self-reported traits and the type of voice that the player has designed for their avatar.

To help the game designers investigate this, please answer the following questions:

Load the data. Data can be found in voiceData.

1. Create scatterplots that plot f0 and pf against the nine personality traits: neuroticism, extraversion, openness, agreeableness, conscientiousness, dominance, and sociosexual behaviour, attitude, and desire. Colour-code the data points by gender.
   • Apply a thin plate regression spline smooth on the scatterplots to visually diagnose nonlinearity. Do you see any possible interactions, linear, or nonlinear relationships in the bivariate comparisons?

2. Create violin plots comparing gender with f0, pf, and the nine personality trait variables. Visually inspect the violin plots and answer the following questions:

• • What is the mean f0 for females and males?
  • What is the mean pf for females and males?
  • What is the mean reported Likert rating for extraversion for females and males?
  • What is the mean reported Likert rating for agreeableness for females and males?
  • What is the mean reported Likert rating for dominance for females and males?
  • What is the mean reported Likert rating for sociosexual behaviour for females and males?
  • Does the shape of the violin plot show that the data has a bimodal, uniform, or normal distribution?

3. Run a linear regression analysis to answer the following questions:
   • Do participants with avatars with lower fundamental pitch report their avatars as higher on neuroticism?
   • Do participants with avatars with lower fundamental pitch report their avatars as higher on extraversion?
   • Do participants with avatars with lower fundamental pitch report their avatars as higher on dominance?
   • Do participants with avatars with lower fundamental pitch report their avatars as higher on sociosexual behaviour?

References for further reading

Stern, J., Schild, C., Jones, B. C., DeBruine, L. M., Hahn, A., Puts, D. A., … & Arslan, R. C. (2021). Do voices carry valid information about a speaker’s personality?. Journal of Research in Personality, 92, 104092.