You can change the Gender of the Native Folk by changing their names. The game currently names them after Italian or Japanese desserts, but you can change those names to typically male or female names by updating the Save.txt file. To do this, after you have saved your file, open that file using Microsoft Notepad. Press CTRL-f to open the "Find" window. Enter {"ID":"Native" into "Find what" and click the "Find Next" button. You will be shown the information about a Native that includes "NM":"name", with the dessert name shown. Simply change the dessert name to another name such as "Cathy", save the file, and load it into Autonauts.
