Kathy,
Could it be that we can be more objective when we study chimps and not be
prejudiced by cultural and neurotic factors? Do people listen more when
you talk about relative weaning ages of other primates than when you talk
about the age in other cultures? Or maybe we think we're "superior" and
have risen above our animal nature. Isn't that part of the reason formula
became popular? It appealed to people to use something "scientific" and
"superior" to what mother nature produces?
-Lucy