In George RR Martin’s Game of Thrones, there are a bunch of characters fighting to rule the seven kingdoms of Westeros.

According to psychologists (who also love Game of Thrones), humans “living in groups rarely form a truly egalitarian society.

Rather, individuals have differing status or rank with the group.” And in this fictional universe, the fight for the highest rank is as much of a mental game as it is a physical battle.

So, could you win the Game of Thrones?

As Cersei Lannister said, “When you play the game of thrones, you win or die.

There is no middle ground.” Yeah, there’s a little at stake.

To play the game, first you have to consider what it takes.

Is it money, strength, or self-control?

Money and strength certainly contribute to how powerful people are, but if you think that’s all – you snow nothing.

Westeros and The Known World is full of competing psychologies, and self-control might be the most important resource for any of the players.

In Travis Langley’s Game of Thrones Psychology, Jones and Goodfriend write, “Self-control might be the key to winning the most important games of all.” But why is self-control so important?

Also known as willpower, it can be defined as “the ability to be in command of one’s behavior, and to restrain or inhibit one’s impulses… self-control is the ability to opt for the long-term outcome.” Self-control is something we all learn with time – as kids we’re generally told things like you can’t have ice-cream until you’ve finished your dinner and even if you want it now, you have to wait, behave and earn your reward.

In the 1960s, American psychologist Walter Mischel developed a simple test of self-control for pre-school aged children, often referred to as “the marshmallow experiment.” Children were given a treat, like a marshmallow and told they could eat it immediately, also called instant gratification.

But if they waited 15 minutes, they would be rewarded with a second treat, also known as delayed gratification.

Self-control is important for more than convincing a scientist to give you more marshmallows.

It’s necessary in social situations where we might need to cooperate with someone else to achieve a goal.

In the words of Ned Stark, “together the pack survives.” And it’s impossible to win the Game of Thrones as a lone wolf.

Sorry Ghost.

For instance, in earlier seasons, although Cersei Lannister mistrusts Lord Varys and would prefer to get rid of him, she decides to keep him around until he is no longer useful to her.

Cersei and many of the other Game of Thrones characters make deliberate decisions that deny immediate gratification and instead work towards a more distant, larger goal.

But self-control is a limited resource–it can be exhausted, like a muscle.

If it’s constantly being used in every aspect of life, like the win-or-die environment of Westeros, eventually self-control will fail and people will make mistakes–like when a very strategic character like Tyrion Lannister takes revenge against his father.

Still, mathematicians have calculated that Tyrion is the most important character, mathematically speaking, in “A Storm of Swords” – the third book and roughly the third season of the show.

By recording any time two characters’ names or nicknames were within 15 words of each other, the mathematicians were able to establish the strength and number of relationships each character had.

Tyrion had the most connections and many of the strongest connections.

Perhaps it was his ability to adjust his behaviors and regulate his emotions to fit the situation.

Perhaps his willpower allowed Tyrion to become the most influential character in Game of Thrones, mathematically speaking.

But, given the environment, willpower is an imperative.

Characters rise and fall based on their ability to regulate their emotions and put off immediate satisfaction for a future reward.

And that even holds true for the real world.

Remember the marshmallow experiment?

Well, Mischel followed up with those kids periodically over the next 40 years.

Those who had more self-control as pre-schoolers tended to maintain that self-control over time.

And that came with benefits: higher SAT scores, better response to stress, lower likelihoods of drug abuse or obesity, better social skills, and a better ability to plan.

In a game of competing psychologies, it seems that self-control could be the key to winning the iron throne.