A research-based program was designed for the improvement of decoding and encoding nonverbal cues as they are important aspects of successful communication and teaching. To extend the scientific base of the program, six correlational studies (N=784) investigated relationships between nonverbal skill and personality dimensions. Low non-significant or inconsistent correlations were found between nonverbal sensitivity and extraversion, directiveness, competence and control orientations, and self-efficacy and "charisma" but significant positive relationships were found between encoding abilities (expressiveness/charisma) and the same personality dimensions (Part I of the paper). Nine experimental investigations (N=392) revealed significant improvements in nonverbal sensitivity, expressiveness, and unambiguousness of communication (Part II). These improvements contributed to significant changes in global personality dimensions: "charisma," extraversion, competence and control orientations, and self-efficacy (Part III). These findings may contribute to the understanding of the nature of personality dimensions as related to their perceptional and behavioral counterparts.