genetics

card 1 of 9 · context meaning

Which meaning of 'genetics' best matches the usage in the sentence?

This amazing occurrence made my head go bong to say the least; it was obvious that Elizabeth had not been “schizophrenic” because of her genetics, nor because of stress, nor malnutrition, nor hypoglycemia, nor because of any of the causes of mental illness that I had learned and rectify, but because of food allergies