She couldn't go into details in a newspaper column, but she did not say there weren't social factors, just that biological factors are also important. 

The Google memo suggested policies that would make the field more attractive to females, like more part-time work, a more cooperative workplace, working in pairs, etc.. Feminists in other cases make the same argument, that the workplace needs to accommodate women's preferences for a more cooperative, social environment, more work-life balance, etc.