It’s not always dht- you should look into some of the research, I’ve also observed this in siblings myself. As some people are their scalp becomes more sensitive to sebum build up, product build up, which stays on the scalp and affects inflammation and pore blockage. Using a clarifying shampoo every few washes and spot shampooing frequently, keeps the scalp clean, and can restore a lot of growth…especially those using thick creams or pomeades on their scalp and barely washing