its not the love that makes a person blind

some interesting observations as mentioned by Andrew W. Luo (MIT, finance) in his talk about efficient markets hypothesis-

While too much emotions hampers an efficient judgemental process, a balance between emotions and reasoning is required to keep a human involved and focussed on his work. A lack of emotional sensitivity may lead to loss of focus on the given task and consequentially the person may spend way too much time on the task at hand.

The prof interestingly correlated the results to the triune structure of human brain consisting of 3 key components- reptilian brain, mammalian brain and cortex (primate brain). Primate brain gives the human capabilities such as planning, logic, analytics etc while mammalian brain handles emotions. Reptilian brain is responsible for very basic and integral functionalities such as temperature control, hunger etc. The responses by three parts supercede others in following order: reptilian > mammalian > cortex. As a result, if any of the mammalian brain controlled action is triggered it gets precedence over primatal functioning. Hence, a trigger of emotions leads to impaired logic => love makes the person stupid :)

On the other hand, damage to mammalian brain causes lack of emotional responsiveness in a person and even though he may be judgementally sound due to a healthy cortex, he may not enjoy doing anything!