What Traits Define A Long-Term Investor?

What does it mean to be a long-term investor? Do long-term holding periods define long-term investing, or are long-term investors better characterized by latitude and intent to focus on long-term outcomes, with a different attitude and mindset?

A research paper from the Brandes Institute, titled What Does It Mean To Be a Long-Term Investor? tries to provide a definitive answer to this question.

The long-term vs. short-term debate, much like investment vs. speculation, has been raging for decades. Trying to reach a concrete definition for either side is difficult because long-term investors, in particular, are not constrained by time. Indeed, one advantage of having a long-term orientation is the capacity to adopt positions where payoff timing is uncertain.