My research project for the next eight weeks consists of examining individuals personalities using various psychological questionnaires and determining how personality effects a persons perception of exertion and pain. I will be collecting data using human subjects who will perform a repeated series of isokinetic elbow flexion contractions through a normal range of motion (5-100 degrees) trying to achieve a peak torque of 75% of their initial maximal voluntary contraction (MVC). The participant will continue this cycle until they can no longer reach the 75% MVC level (signifying 25% fatigue). The purpose f this study is to investigate if we can determine which individuals differences, i.e. normal personality trait and genetic phenotype contribute significantly to inter-individual variability in the perception of pain during dynamic muscle fatigue. Psychological individual differences, particularly neuroticism or negative affect have been consistently demonstrated to be associated with symptom reporting and pain perception in patient populations. The long term goal of this line of research is to determine factors responsible for inter-individual differences in normal psychological traits contribute to the wide variability observed in musculoskeletal pain perception.