People nowadays are very preoccupied by their physical health, taking every measure which their pocket allows in order to drive away any kind of biological or chemical contamination. The problem is that people are not well aware of another serious type of contamination which affects their mind, their judgment and their actions in various domains of life. Psychological contamination refers to that process in which one hears/reads information without knowing it, afterwards finds out that it was false and he normally decides to forget it. The problem is that the false information is not driven out of our minds, but it just goes under another level of neurological activation. In other words, the information does not consciously influence us, but unconsciously. This is already a fact which has been proved throughout many studies carried in the last decades. The theory which explains this process is derived from an old philosophical debate between Descartes and Spinoza. The first one said that a person first hears the information, then he understands it and only after assigning it with the value of truth, the information is coded in the memory. The later sustained the idea that a piece of information once heard is directly coded as true in the memory and only afterwards one begins to understand it and decide whether it's true or false. Science has tested these two perspectives and it concluded that Spinoza was right. Therefore, what comes to our ears is automatically and unconsciously considered true. There are though some techniques which can stop contamination. The most efficient technique is called the technique of the alternative and incompatible information. This refers to the identification of the false information and then the replacement of it with another piece of information which is alternative, meaning that it has the same purpose or function, and it is also the opposite of the false information. For example, if a person finds out about a friend that he loves to steal others' goods but eventually he discovers that it was all a big lie, in order not to get contaminated by this information and have some doubts when living valuable items close to him, that person should admit that the heard information was false and also replace it with the fact that actually his friend is very honest and he does not take what is not his property. A counterexample would be to replace the fact that he likes to steal with the fact that he is handsome and punctual. This wouldn't stop the contamination. Another technique is called the rational anticipation technique and is very similar to this one, just that it has another step before replacing the information with new alternative and incompatible one. This step implies the identification of the magnitude of the contamination, its consequences and also specific details such as when it could occur. This first step has the role of motivating to take action against it. One may thing is that, these techniques take time and maybe they are not worthwhile. These arguments could be considered valid when the serious implications of psychological contamination are not taken into account. In order to emphasize these implications there will further be presented an example of an experiment: There are 2 groups. The first group, which is the control group, receives the description of a crime and it is asked to decide the number of years of jail the criminal should receive. The other group received the same crime description accompanied by another description of the criminal which says he also used to abuse his wife and children and always fights with his neighbors. Then the group is told that the information about the criminal is false and only the crime description is valid. This second group is also asked to do the same thing as the control group. Results show a significant difference in the number of years of jail given by the two groups, the second one giving a much more difficult penalty. In conclusion, not only our body can get contaminated, but also our mind. False information can distort our judgements and behavior. The consequences may not always be as severe as presented in the example, but they can be that sort which describes broken relationship or different kinds of stereotypes.