We seem to have a disproportionate number of sayings and heuristics making us less impulsive and making our time horizons longer. That might have developed as a way of sustaining the long-term discounting we humans have in comparision to other animals; http://www.wjh.harvard.edu/~mnkylab/publications/animalcommunication/constraints.pdf has a nice diagram (figure 3) showing the difference between human (slowest), rats and pidgeons (fastest discounting). Slow discounting might be linked to our foraging lifestyle, http://www.wjh.harvard.edu/~mnkylab/publications/animalcommunication/constraints.pdf but since human societies have developed quickly recently the benefits of discounting have risen faster than evolution could have adapted (or impulsive individuals have a fitness advantage by having children earlier).

So maybe we have a culturally transmitted bias towards slow discounting and persistence, that normally counteracts our too fast discounting. But in some individuals it becomes maladaptive, perhaps because they already are naturally stubborn.