ONE RING TO RULE THEM ALL...

In the last need, Smeagol, I should put on the Precious; and the Precious mastered you long ago. If I, wearing it, were to command you, you would obey, even if it were to leap from a precipice or to cast yourself into the fire.
- Frodo

Now that all the obedience stuff is posted up in Social Psychology, I can turn my attention to what's really vexing me: The Lord of the Rings. Specifically, Gollum. So just why, psychologically-speaking, does Gollum serve Frodo so eagerly. And why does he betray him at the end? What can the psychology of obedience tell us about this?

'Smeagol,' said Gollum suddenly and clearly, opening his eyes wide and staring at Frodo with a strange light. 'Smeagol will swear on the Precious.'
Frodo drew himself up, and again Sam was startled by his words and his stern voice. 'On the Precious? How dare you?' he said. 'Think!
One Ring to Rule them all and in the Darkness bind them.
Would you commit your promise to that, Smeagol? It will hold you. But it is more treacherous than you are. It may twist your words. Beware!'

Milgram's Agency Theory suggests we all enter "agentic states" in the presence of authority figures. We can resist this "agentic shift" if the authority figures commands us to do things that go strongly against our wishes, but the "moral strain" this produces is uncomfortable. It's easier to let yourself become an agent, then you can hold the authority figure responsible for anything you do at their command.
This seems to fit Gollum pretty well. Frodo orders Gollum to take him to Mordor, which Gollum doesn't want. Moral strain ensues. In the 2002 film of The Two Towers, director Peter Jackson cleverly plays out Gollum's strain (delightfully acted by Andy Serkis) as a mental battle between "nice" Smeagol and "nasty" Gollum.
But what makes Frodo an authority figure in the first place? It's the Ring, of course. Milgram noticed how "symbols of authority" turned an ordinary Biology teacher, Jack Williams, into the stern Experimenter who must be obeyed: a white lab coat, a clip board, the advanced science of the shock generator, the prestigious setting of Yale University. When Milgram took away some of these symbols, in Variation #10, which was set in a run-down office that had no connection with Yale, then obedience dropped from 65% top 45.5%.
In Tolkien's world, the Ring is the ultimate symbol of authority - although Aragorn's reforged sword Anduril which enables him to command the dead men of Dunharrow in The Return of the King, runs it a close second.

"Master betrayed us. Wicked. Tricksy. False. We ought to wring his filthy little neck. Kill him! Kill him! Kill them both. And then we take the precious and we be the master!"
- Gollum

It's not quite that clear though, is it? Because Gollum does disobey... he abandons the hobbits in Shelob's lair.
Milgram could explain this, up to a point. Obedience isn't always blind obedience and agents still have wishes of their own as well. In Variation #7, Milgram had Mr Williams phoning in his orders. The participants still obeyed, but they sneakily flicked lower-voltage switches than the ones they were supposed to, if they thought no one was observing them. This is a bit like Gollum: they were obeying, but they tried to subvert the orders, twisting them to their own wishes while still "going along with" the authority figure.
If we bring in Social Impact Theory, it gets a bit clearer, because Impact Theory looks at how many people are giving the orders and how many are receiving them. Throughout most of the story, Frodo and Sam gang up on Gollum: there are two of them and one of him, which increases the Social Force of Frodo's orders. Once the hobbits get to Cirith Ungol, Gollum has backup in the form of a giant spider.  Frodo's authority doesn't have the social impact it once had and Gollum is free to rebel openly.

It's often said that a good book or film gives us characters who are psychologically real - they react the way real people react, even if they're reacting to fantastical things like giant spiders. I think The Lord of the Rings acts as a good parable about obedience and agency. I hope this blog has illuminated MIlgram's theory and Social Impact for you as well.