I have a cousin who used to be a research engineer at MIT until recently, and now is the global manager of a company. While at MIT, he suggested that I should apply for graduate school there (I'm an undergrad in Mechanical Engineering in Brazil). He knows me pretty well and is encouraging me to try. I have a good GPA, 3.6/4 as of now, but could be 3.8/4 by the time I graduate. I also have published papers, some of which will be published in top journals. Since he used to be part of the MIT community, would a recommendation letter from him be an advantage for me? Or, because he's family, the comittee could simply consider it biased?
PS: He was not from the mechanical engineering department.