Yeah it is used for comparisons.Wouldn't 同じ be used for a comparaison between 2 things if it had a meaning of "same or similar"?
For example: 同じ女の子でもこんなに考え方が違うんだね。
同じ大学出身でもこんなに頭の良さが違うんだね。
It's often used as a comparison when one aspect is same, but the other traits are different. Is this what you and 六道仙人 are asking?
Edited by ramenanmitsu, 12 May 2014 - 12:05 PM.