When I took my choice in general I look for faces that reflect maturity, self-confidence and wisdom in dealing with the internal affairs of the tribe, and faces that reflect intelligence, security and firmness in facing external problems.
And that's a problem IMO. Does everyone agree on what face reflects maturity, self-confidence and wisdom, or intelligence, security and firmness? Or will that depend on a person's life experiences with people. Like Laura's oft-quoted story about the "man in the blue hat" where a person's negative experience with someone with certain characteristics (including physical) - where the specific characteristics are not implicated in the negative experience - can forever influence that person's perception of anyone with the same or similar characteristics.
All of this reminds me that its very difficult (or impossible) for a single person to navigate reality effectively, and a group is needed to do so.