“It’s called Love Island, not Friend Island” – Is being a snake the best strategy?

The Game

Love Island is sweeping the country by storm this year. If you’re out of the loop, it’s a reality show where singles “couple up” in a villa in Mallorca where they develop relationships and try to find “love”.

The original crew. Don’t even remember half the boys any more.

When they first arrived at the villa, the girls picked their partners in the first “coupling”. At subsequent weekly recouplings, they are allowed to pick different partners. New contestants enter every week and players are evicted if they are not in a couple.

If you think about Love Island in relation to Game Theory, you can see that it is an example of the Prisoner’s Dilemma game.

Prisoner’s Dilemma Game

The Prisoner’s Dilemma is the famous paradox analysed in Game Theory which demonstrates how two individuals can end up not cooperating out of self-interest, even though cooperating would result in the ideal outcome.

In the Prisoner’s dilemma*, two criminals are arrested, let’s call them Jonny and Mike. Jonny and Mike have been caught breaking into Theo’s house. The police take them to the station and interrogate them in separate rooms so they have no way of communicating with each other. There is only evidence of their break-in, but the police believe that they intended to burn Theo’s house down. Therefore, the prosecutors do not have enough evidence to charge them with arson.

Prisoner's Dilemma Convicts
I hope no one finds this pic randomly on Google and takes it seriously hahaha

In the interrogation, if Jonny and Mike cooperate by both remaining silent about intending to torch the place, the police cannot charge them with arson. The police can only charge them with breaking and entering so they will be sentenced to just one year in prison (these are of course only examples to illustrate the game, I have no idea about criminal law!).

Buzz Lightyear
Actual footage of Jonny’s interrogation.

If Jonny and Mike don’t cooperate and they both confess their intention to burn down the house (i.e. they defect), it’s a much more serious offense so they will both be sentenced to 10 years in prison. Mutual defection = bad outcome for both.

If only one of the pair defects and the other cooperates, the defected player is rewarded for confessing and is set free whereas the one who stayed silent gets an even harsher punishment of 15 years incarceration. Basically, if Jonny snakes Mike, he can go free with 0 jail time, whereas Mike will be imprisoned for 15 years.


A payoff table makes it a lot easier to see the outcomes whilst taking each player’s strategy into consideration.

*This version of the Prisoner’s Dilemma is based on the University of Tokyo’s Coursera course.

Looking at the Payoffs

Payoff Table

As we can see from the table, the most beneficial strategy for both prisoners is to cooperate and stay silent; Jonny and Mike would only spend one year in prison each (-1, -1). However, the most “rational” strategy for them would be to defect even though it has a longer prison sentence (-10, -10). If Mike chooses to stay silent, but Jonny decides to confess, Mike would be incarcerated for 15 years whereas Mike would go free! Therefore, to protect himself from being “mugged off”, the rational thing for Mike to do is to confess.

There is a high risk of Jonny preserving his self-interest and selling out Mike so it would make sense for Mike to confess to save himself from the maximum sentence. But, regardless of Jonny’s strategy, confessing (defection) would still be the best choice because cooperation is a dominated strategy. The payoff for cooperation is always less than for defection.

If it’s assumed that Jonny will cooperate, Mike will have a better outcome by defecting because 0 years incarceration is better than 1 year (0 > -1). If it’s assumed that Jonny will defect, Mike will still have a better outcome by defecting because 10 years incarceration is better than 15 years (-10 > -15).

Therefore, if the prisoners are purely rational, the best option would be to betray each other. This best option is called a Nash Equilibrium (circled in the table). Keep an eye out for my upcoming post explaining the Nash Equilibrium!

Love Island Dilemma

We can model the Love Island couples on the Prisoner’s Dilemma. Since the outcomes of the players’ strategies are not quantified, I will use ordinal numbers to represent the attractiveness of each payoff.

Let’s use Sam and Olivia as an example. Sam and Olivia were coupled up nicely until Chris entered the villa. Between the couple, their strategies can be simplified to:

  1. staying together (cooperate) or
  2. dumping each other (defect).
When you see someone who’s 100% your type on paper.

From Olivia’s point of view, these are the four possible outcomes in this situation in order of attractiveness (least attractive payoff = 1, most attractive payoff = 4):

  1. Lose security of being in a couple and receive backlash for being a snake
  2. Stay safe but be in a lacklustre relationship
  3. Lose security through a mutual break-up but retain good reputation
  4. Get to couple up with a newcomer (i.e. Chris)

Love Island Payoff Table

As we saw in the Prisoner’s Dilemma, cooperating is a dominated strategy. Regardless of what Sam does, it’s better for Olivia to defect and vice versa. Defection yields a higher payoff in both strategies. We saw this for ourselves when Olivia indeed broke up with Sam when Chris entered the villa.

Don’t hate the player, hate the game

As the narrator constantly reminded us, “it’s called Love Island, not Friend Island”. The contestants value their friendships but they are there to win the game. Naturally, their self-interest will tempt them to betray. Also, picking the rational but slightly traitorous strategy protects players from being “pied off”.

Pie in the face!

That is not to say that they should disregard their friendships. Humans are social animals so social pressure is a strong deterrent to ruthless behaviour. In reality, people show a bias towards cooperation in these types of games. An MRI study using the Prisoner’s Dilemma showed that cooperation activates the reward centres of the brain. Cooperating makes us feel good!

Even if the player is only focused on winning the game, they still need to keep in mind the public’s perception. If they are unpopular due to their snakey actions, they risk elimination and rejection from the social group.

Ultimate rejection.

Furthermore, a true Prisoner’s Dilemma is only played once but Love Island continues so it’s actually an Iterated Prisoner’s Dilemma – where players learn and adapt their strategy with each cycle of the game. I will discuss this in an upcoming post!

Therefore, “being a snake” may be the best strategy “on paper” but it ultimately depends on what the player’s personal goal is. What does the player consider as winning? Finding love, making great friends, and winning the cash prize could all be considered a win; it just depends on what the player wants the most.

So what’s the point of Game Theory?

Many external factors are involved in decision making which are not represented in the Prisoner’s Dilemma. It would be practically impossible to factor in all the different facets involved. However, the Prisoner’s Dilemma is an interesting model to show what would be the best option if all players were clinically rational. By simplifying the problem, it allows us to analyse and focus on the key elements. It’s not a crystal ball but it does give compelling insight, just like a line of best fit does for data.

Love Island may be one of the sillier things to apply Game Theory to, but Game Theory has so many real world applications. By studying the strategies, we can come up with ways to encourage cooperation. Sure, this wouldn’t make for entertaining TV viewing, but we should strive to have more Camillas in a world full of snakes.Shock


What does Game Theory have to do with Reality TV?

Hi there! If you’ve somehow managed to stumble across my blog, I assume you’re either interested in Game Theory or reality TV, but most probably not in both?

You’re probably wondering how on earth this blog idea even came to being with these two very contrasting topics. Let me explain…

Blame it on Love Island

It all started off with me binge watching Love Island on one lazy weekend.

Eye roll
I can hear your eye roll from here.

Don’t judge me, we all have our guilty pleasures, reality TV just happens to be one of mine. I’d heard about it all over social media and there were some hilarious memes but I never knew what the hype was about so I decided it was time to join the masses.

If you’ve never heard of Love Island, it’s your typical trashy British reality TV show. The premise is that a bunch of tanned singles are put together in a villa in Mallorca to “find love” and the producers introduce a series of constructs to stir up drama. Contestants need to “couple” up and anyone not in a couple gets eliminated. Another monkey wrench is that some new people get introduced partway which leads to more people getting voted out and heightened tensions.

Actually, in terms of the rules in this competition, it’s a bit of a mess. I honestly couldn’t pinpoint the exact rules since they seem to introduce something new every week but you just kind of go along with it for the sweet sweet drama.

How did binge watching this mind-numbing show inspire me to learn about Game Theory?

One of the contestants (Olivia) faced a dilemma in an episode where she could either stay safe in her pre-existing couple or take the risk of “dumping” him for a new guy that she fancied. Is it better for her to choose safety or to follow her heart?


I wondered about her decision making process which led me to do a little research into Game Theory which in turn allowed me to have a better insight to her decision making behaviour.

What is Game Theory?

I’m just going to briefly explain Game Theory in this post as it definitely deserves a whole post for itself. For now, I will just give a basic definition. Game Theory uses mathematical models to map and study the interaction of groups in rational decision-making and is also referred to as the ‘theory of social situations’.

Game Theory can be used to analyse different social situations and in doing so, can help us better understand negotiations and cooperations as well as strategies to reach ‘best situations’. The scope of Game Theory covers everything from modelling economics and business to biological behaviours. In terms of social situations, what better way to examine social behaviour than in a reality TV show?

Learning more about Game Theory

My degree was in Psychology so I’ve had a little introduction to Game Theory when we studied the ‘Prisoner’s Dilemma’ (don’t worry, I’ll get to this soon). However, I am by no means an expert at Game Theory at all. I decided to enroll on this an amazing Coursera course about Game Theory and I started this blog to consolidate my knowledge (as well as justifying my fix of trashy TV). I hope we can learn about Game Theory together whilst bonding over our love-hate relationship with trashy TV! 😊

Stick around for my reality show analyses, more will be coming very shortly! If you’d like to find out more about what I thought about the Coursera course on Game Theory, check out my post on my other blog, MateMake.