A 2005 Duke University study found that macaque monkeys preferred to follow a "risker" target, which gave them varying amounts of juice, over a "safe" one, which always gave the same - they just like gambling. Intriguingly, the monkeys preferred the riskier target even when it gave them consistently less juice than the same one, and continued to choose the riskier target in the face of diminishing returns when a single large one was still in memory.- From Roll the Bones: The History of Gambling by David G. Schwartz
This explains much.
Not the least of which is why some primates, most notably the Middleboro Board of Selectmen and Friends continue to support, embrace, champion and believe in the continuing long shot of a casino in their midst.
Keep on reachin' for that rainbow Middleboro Board and Friends.
...I mean macaques.