Are some (human) races more dominant than others in certain facets of existence by their genetic structure alone, or is the mind more capable of influencing one's tendencies towards excelling in certain facets of existence?

Example: A Germanic man is competing against a Negroid man in (insert subject/field/area here).

Who wins? Why?

Would the Germanic man win because he is genetically superior?

Would whoever more believed that they were superior win?
(the latter assumes that they have the same ability and knowledge in this case)

A simplification of the question may be this: Can confidence overcome genetic disadvantage?