Abstract
Objective: To analyze the subjective quality of sleep and the expression of anger according to the position adopted during sleep.
Methods: Using an ex-post facto design and an incidental sampling procedure, 729 university students participated in the study, 63% of which were women. The subjective quality of sleep was assessed using the Pittsburgh Sleep Quality Index (PSQI) and anger was measured using the State-Trait Anger Expression Inventory-2 (STAXI-2). One question was used to determine the body position: "Normally, what position do you adopt when sleeping? [Right Lateral Decubitus (RLD), Left Lateral Decubitus (LLD), Supine Decubitus (SD), or Prone Decubitus (PD)].
Results: 42.4% reported sleeping in the RLD position, 29.2% in LLD, 10.6% in SD and 17.8% in PD. Women tended to sleep in RLD and not in SD, while in men there is a tendency to sleep in the SD position and not in RLD (χ2 (3,729) = 15.119, p <.002). People who reported sleeping in RLD appeared to have poorer quality of sleep compared with the group that reported sleeping in LLD. Those who adopt the PD position show worse scores on the scales measuring Feelings of Anger, Trait-Anger, Temperament of Anger, Index of Expression of Anger, and External Expression of Anger.
Conclusion: The data appear to support the existence of relationships between the posture adopted during sleep, the subjective quality of sleep, and emotional states. In future research it will be necessary to apply methodologies with greater control of the variables along with objective measures of body position.

Key words: Key words: Anger, sleeping position, subjective quality of sleep, college students,