My grandmother, father, and brother all have psoriasis, is it likely that i will get it too?

Maybe: It is more likely than the general population. 70 per cent of people with psoriasis have a family history of psoriasis. With multiple family members it is possible but not 100%.

Psoriasis: Autoimmune disorders, such as psoriasis, do have a much higher rate of genetic components and hereditary transfer. Although your risk is increased, it is definitely not a guarantee you will develop psoriasis.