Emotion as a Way of Knowing

What are Emotions? I found that defining the term emotion wasn't that easy. According to the Oxford Dictionary, an Emotion is a strong feeling deriving from one’s circumstances, mood, or relationships with others. On Thursday (yesterday) in The Theory of Knowledge's Class we held constructive discussions in our groups and class on 'Emotion as a Way of Knowing'. I disagree to a certain extent with this definition. Emotions are not necessarily "strong" feelings. I can have opinion about something without having strong emotions.We all discussed whether emotion and logic were separate entities or combined forces. We need our emotions to survive (such as keep safe) and respond to the actions and other living organisms.  I personally believe that emotion and logic/reason work together; they are combined forces. We need to use some of our emotions to reason. Do I prefer one over the other? I honestly do not know.We also watched a clip from the 2006 FIFA World Cup final match France against Italy when Zinedine Zidane head-butted  Marco Materazzi of Italy. I remember that day clearly when I watched 2006's World Cup. We debated whether or not Zinedine was being ruled by emotions or logic, and or both and if we were in his position would we have done so. As a footballer/contact sports player, I, of course would have head-butted  Materazzi if he provoked, tripped or swiped me. I am not sure who started it, but if Zidane did I would have fought him. That is a signal that you want to fight me and an insult. There is no other option but to fight. I know that we Footballers and other contact sportspersons can get very emotional during a game and logic normally goes out the door. In Zidane's case I think he was being emotional and his reasoning became limited, it was his last World Cup match so I guess he thought, why not?
Several problems can arise when we use Emotion as a Way of Knowing. When emotions get too high they can overrule logical thought or reasoning causing us humans to act or respond irrationally to the events or others around us. This can have grave consequences in our relationships. It can be very biased or possibly wrong when we try to use emotion as a way of knowing because it is really an assumption, not proven, not a fact. Such as when we judge someone based on first impressions. Sometimes we do not really know someone, even when we think we might know every fiber of their being and we definitely don't know someone unless we make the effort to get to know them.