What are biological primary mathematical skills? In doing a bit of background reading for this question I came across a section in the book Cognitive Neuroscience: The Biology of the Mind on page 602 stating:


  There are no sex-related differences in biological primary mathematical skills, even in nonhuman primates


And later defines secondary mathematical skills as 


  the kinds of math taught in schools in the industrialized world


But it doesn't define what primary mathematical skills are.

Can anyone explain what is meant by the term?

Cognitive Neuroscience: The Biology of The Mind, 2nd ed. M. S. Gazzaniga, R. B. Ivry, G. R. Mangun.
The term seems to come from David C. Geary's 1995 article. Here's the abstract with full-text link below:


  An evolution-based framework for understanding biological and cultural
  influences on children's cognitive and academic development is
  presented. The utility of this framework is illustrated within the
  mathematical domain and serves as a foundation for examining current
  approaches to educational reform in the United States. Within this
  framework, there are two general classes of cognitive ability,
  biologically primary and biologically secondary. Biologically primary
  cognitive abilities appear to have evolved largely by means of natural
  or sexual selection. Biologically secondary cognitive abilities
  reflect the co-optation of primary abilities for purposes other than
  the original evolution-based function and appear to develop only in
  specific cultural contexts. A distinction between these classes of
  ability has important implications for understanding children's
  cognitive development and achievement.


You can read more about David C. Geary's articles on mathematics on his website.

References


Geary, D. C. (1995). Reflections of evolution and culture in children's cognition: Implications for mathematical development and instruction. American Psychologist, 50, 24-37. FULL TEXT