Tindle explained that, in general, optimists tend to experience less stress than pessimists when faced with problems, and they tend to assess the situation, cope with the problem head-on, and mobilize support to solve issues, more so than pessimists.

CNN: Optimistic women may have lower risk of heart disease

"I think we know the situation in domestic football in both Poland and Ukraine and I'm afraid the documentary hit the nail on the head -- it's a very bad situation, " he said.

CNN: STORY HIGHLIGHTS