The primary reason that southern men are more aggressive than northern men is that:

the invasive species was introduced due to commercial purpouses, as there was a demand for fur clothes and hence, a business opportunity connected to this product. actually, it was when the nutrias scaped, causing harm to the us ecosystems when they acquired the status of invasive species. in this case they have caused an environmental problem, but it could have affected also economic interests or even human health.

the technology changed agriculture in an impacting manner since many people left the field work by a cellular or other technological appliances