Most Helpful Guy
"Success," like many things, is individually determined. So it can be argued that, if "success" for a person involves things like happiness, quality of life, joy, and pleasure, then yes, positivity in and of itself would help "make" a person with those values successful.
For a person measuring success by financial wealth, positivity might help to some extent, but financial gain sometimes depends on qualities like self-centeredness, willingness to objectify and exploit others, disregard for ethics, etc. So there the overlap is not so clear.0