Most societies are structured hierarchically. People in certain positions hold authority over the rest of us e.g: parents, teachers, police officers, nightclub bouncers. We obey people further up the social hierarchy
The power that authorities wield is legitimate because it is agreed by society. Most of us accpet that authority figures should exercise social power over others toallow society to function smoothly
People with legitimate authority have the power to punish others. We give up some independence to people we trust to exercise authority properly. We learn to accept authority during childhood (parents, teachers etc)
History has shown that some leaders (e.g: Stalin and Hitler) use legitimate authority destructively, ordering people to behave in cruel and dangerous ways
One strength is legitimacy can explain cultural differences. Research shows that countries differ in obedience to authority. For example 16% of Australian women obeyed (Kilham and Mann), 85% of German participants did (Mantell). This shows that authority is more likely seen as legitimate in some cultures, reflecting upbringing
One limitation is legitimacy cannot explain all (dis)obedience. People may disobey even when they accept the legitimacy of the hierarchal authority structure. For example Rank and Jacobson's nurses were disobedient, as were some of Milgram's participants. This suggests that innate tendencies towards (dis)obedience may be more important than legitimacy of authority