Final answer:
The pioneer in sport psychology who employed a scientific approach to study character development in sports is not detailed in the provided text. However, Wilhelm Wundt is a foundational figure in psychology who applied scientific methods to study consciousness, and Hugo Munsterberg made significant contributions to applying psychology to industrial and organizational settings.
Step-by-step explanation:
The early pioneer in sport psychology who took a more scientific data-based approach to psychology, and saw sport as an excellent way to demonstrate the value of this "new scientific psychology" and to investigate character development in sport, is not explicitly listed in the provided reference material.
However, historical contributions to psychology as a science can be accredited to several important psychologists from the 19th and early 20th centuries. Wilhelm Wundt, often credited as one of the founders of modern psychology, viewed psychology as a scientific study of conscious experience and used introspection to analyze the components of consciousness. Furthermore, Hugo Munsterberg, a student of Wundt's, made significant contributions to industrial and organizational psychology, some of which involved the study of employee selection, training, and advertising that somewhat intersects with the principles of motivation and performance studied in sport psychology.
As the provided materials do not outline the specific early pioneer in sport psychology, one would have to conduct further research to definitively answer this question.