How do you get lice when its not from other people or animals?

I feel sorry for white people because they get lice and black people don't(experienced from my bff Michaela). I'm Latina, French, and dutch and I never got lice. You can get it from these reasons below.

1. Not washing your hair enough

2. Your scalp is too dry

3. If you have bad dandruff and you don't have dandruff shampoo.

4. From itching your scalp.

Watch out for those reasons.