A 15-year study of young people in Finland found that education level, nonrational thinking, cognitive potential, and cognitive performance were not associated with social intolerance -- i.e., intolerance toward different attitudes, lifestyles, cultures, or values of others. On the other hand, higher social intolerance was associated with low flexibility, high perseverance and low persistence. The study was published in Brain and Behavior. ...
Ehhhh kinda sounds like another mid study that tries to simplify such an abstract concept such as tolerance and intolerance, though is interesting they had people self reported as non-flexible in thinking/attitude being the least likely to be tolerant.