Neuromuscular and sociolinguistic hypotheses were proposed to explore and account for the nature of individuals' idiosyncratic speech rates. One hundred subjects (50 males and 50 females) read the Farm Script passage at both habitual and maximum rates. FAST and SLOW subgroups of subjects were selected for both genders based on their overall speaking rates. The articulation rate data derived from 30 selected subjects (SLOW and FAST) revealed the following findings: (a) a significant linear regression function existed between the habitual and maximum rates, (b) significantly different maximum rates were found for the SLOW and the FAST groups, (c) roughly equivalent relative changes from habitual to maximum rate for both SLOW and FAST groups. No significant gender differences were found across different speech tasks and measures of speech rates. The weight of the evidence seems to suggest that neuromuscular constraints play a role in the determination of an individual's habitual speaking rate. Nevertheless, the study did not suggest that either neuromuscular hypotheses or sociolinguistic hypotheses alone can account for the control of individuals' speaking rates due to the unusual ability demonstrated by a few subjects in the SLOW group, to speak at very fast maximum rates.