> How can I tell if I'm self limiting or if I'm being environmentally limited?
Are you voluntarily having fewer kids than you physically could, or did you starve to death?
If you fear your kids would starve or otherwise have a terrible life, and you voluntarily do not inseminate - I think it could be argued that you are volunteering - however I think it's a reaction to the environment and a calculated view of what's to come.
That's a self limiting decision. It's easy to rationalize yes