The peroxide effect is observed in case of HBr and not with HF, HCl or HI. Give reason.

Why peroxide effect is not applicable to HCl and HI?

Anti Markownikov rule or peroxide effect applies to the addition of HBr only and not to the addition of HCI or HI give reason.

In the presence of peroxide addition of HBr to propene takes place according to anti Markownikoff's rule but peroxide effect is not seen in the case of HCl and HI. Explain.