I do not know whether you can change your brother or not. But human beings also have a free choice between different alternatives. Depending on how you choose, you can get very different results.
One of the main differences between humans and other animals, is that humans are less controlled by genetics and more controlled by learning and personal choice. This is one of the main reasons for the success of the human species.
Experts differ in opinion on to what extent humans are controlled by inheritance. But also those experts who believe that we are partly controlled by inheritance also accept that learning and personal choice is also important.
You could tell your brother that the ability to choose and control your own behaviour is something which is caused by genetic inheritance.