Fifa's decision to hand Luis Suarez a four month ban for biting Italian defender Giorgio Chiellini has sealed Suarez's place as the villain of World Cup 2014. The incident has provoked outrage across the globe, with many saying the punishment is too lenient for such a heinous crime.
But where does this behaviour that we find to be so unsportsmanlike come from?
Suarez is not the only culprit: diving, dirty tackles and other foul behaviour takes place on the pitch that leaves us wondering why players sometimes act this way.
Sports psychology research shows that clearly there are some personal characteristics that predispose players to cheat, but the social environment also plays a key role.
The aim of the game in football is winning, with the World Cup being the pinnacle of the sport. Unsurprisingly, cheating is largely driven by a desire to succeed.
There are two types of success: objective and subjective. Objective success is measured by the number of goals a team scores, which determines who wins the game. But there is also subjective success. This can apply in the face of defeat and is where players have their own definition of success, which they develop over time through socialisation with significant others such as family and coaches.
Players who cheat often have big egos, and a disposition to define success in relation to others. For these players, satisfaction with accomplishment is dependent on doing better than others.
In contrast, other players are predisposed to feel successful when they accomplish victory through hard work and achieve a personal best. Success for these players has value and meaning when achieved not through cheating but through personal effort. Players who prioritise ego tend to cheat and injure others, whereas those who value tasks are more likely to play by the rules.
Footballers differ in the importance they place on being a moral person. Some feel that certain traits such as being fair and honest are an important part of their identity and this motivates moral action.
In one study, we found adult football players who had a strong moral identity reported low frequency of anti-social behaviour such as diving, deliberate handballs, and trying to injure an opponent while playing football. It's unlikely that Suarez would fall into this camp.
Although individual differen- ces distinguish football players who cheat from those who don't, the most important influence comes from the team environment, particularly the coach. Through the rewards they give and the way they interact with players, coaches communicate what is important in football.
For example, when coaches reward only the best players, and pressure players to win, they send a clear message that winning is everything. Similarly, when coaches encourage their players to dive, they send the message that this behaviour is acceptable. This makes players who contemplate diving and dirty tackling actually engage in these acts.
In another study, we asked football players to read scenarios that referred to hypothetical situations in football, such as diving to fool the referee and dirty tackles. Players who perceived that their coach encouraged this behaviour and favoured the best players also reported cheating. Interestingly, these players also thought it was right to do so: that is, they did not have reservations about the acceptability of diving or dirty tackling.
We observe the same players cheating over and over again - Suarez, for example, is on a third charge of biting an opponent and he's trying to play down its significance.
Many are shocked at the apparent lack of guilt or shame on his part, which are the emotions that typically deter people from immoral behaviour. How do these villains on the pitch act the way they do without feeling bad?
Behaviour is justified through moral disengagement, which is a set of mechanisms people use to justify cheating or other forms of inappropriate behaviour.
For example, footballers may displace responsibility for their actions to their coach, by saying that the coach told them to do it; they may blame players of the other team by claiming that they provoked them; they may say that they did it to help their team; they could downplay the consequences of their actions for others; or they could say that "everybody does it".
These justifications enable footballers to minimise negative emotions that are normally experienced when one cheats. In several studies we have found that football players who report high moral disengagement also report high anti-social behaviour.
The answer to better on-field morals lies in the players' immediate social environment - that is, their teammates and manager. Coaches especially play a pivotal role in behaviour. The way they respond when a player cheats sends a message to the player of whether this behaviour is acceptable. Suarez received strong backing from his coach, teammates and much of the Uruguayan press.
Fifa's decision to give Suarez a four month ban, curtailing his involvement in Uruguay's World Cup campaign, sends the message that this behaviour is unacceptable. But this is not the first time Suarez has acted this way and been punished.
Given that this behaviour is recurring, a more severe punishment would have been more likely to act as a deterrent for future anti-social behaviour. Clearly though he would also benefit from a social environment that doesn't encourage this kind of behaviour as well.
Maria Kavussanu is a Senior Lecturer in Sport and Exercise Psychology at University of Birmingham, United Kingdom. This article first appeared in The Conversation (theconversation.com), a website which carries analysis by academics and researchers in Australia and the UK.