“…the Mishnah in Pirkei Avot… enumerates the 48 qualities… essential in order to acquire Torah. One of the requisite virtues is ‘hanoseh b’ol chaveiro’, (participating with someone else’s troubles).

…Gemara in Eruvin, 13b… states that with regard to the halachic disputes between Beit Hillel and Beit Shammai, that the law follows Beit Hillel, even though Beit Shammai were smarter. The reason for this is because Beit Hillel would always speak out the opinion of Beit Shammai as well as their own, and they would first quote Beit Shammai before stating their own opinion. The simple understanding of this is that as a reward for their humility, the halacha follows Beit Hillel. 

… By speaking out the opinion of Beit Shammai, they were exercising the trait of empathy – understanding where the other person is coming from. This enabled them to fully understand opposing opinions and then come to a truthful conclusion. This is the reason why empathy is a required trait for one who wants to acquire Torah. A self-absorbed person will be unable to entertain alternative opinions and so will be limited in his ability to develop a well-rounded approach to the Torah.”