Another possibility, very obvious, is homophily, or, birds of a feather flock together; here, I form my tie to you because you and I share a similar body size.
另一种可能，很显然，就是同类的聚合效应， 物以类聚、人以群分。 我之所以和你建立关系 正是因为我们俩身形相似。