I'm starting to prepare my application for scholarships to do MSc in Europe. One of the requirements, of course, is the motivational letter. I was interested: how personal should the essay be? How many hints about your passion in the chosen MSc programme are ideal? I don't want to sound pathetic and unrealistic in my application and will try to convey as realistic motivational goals as possible in the letter. But are there boundaries where being too personal in your statements will be considered a negative thing?
Passion is good, but passion alone does not make a successful student. You also need to talk about your academic achievements and interests in a realistic manner, and emphasise how your qualifications and aims make you a good fit for the particular MSc you're applying to.
Emotive statements which use time honoured clichés such as "I've been interested in physics ever since I took my first trembling steps into the subject" should definitely be avoided.
Academic writing should be crisp and clear and ultimately there is little room for sentiment. If you can convey your motivations in that style your statement will likely be much better received than an incoherent or overly emotional letter.
Note: the answer to this may be somewhat dependent on the local academic culture (you don't specify where in Europe you're applying) but I think it's broadly true that too much emotional writing will have a negative effect.