The research has shown that washing hands with soap and water makes people view unethical activities as more acceptable and reasonable than they would if they had not washed themselves.
To reach the surprising conclusion, 22 people who had washed their hands, and 22 who had not, were made to watch a disgusting scene from the film Trainspotting, about heroin addicts.
All the participants were then asked to rate on a scale of one to nine as to how morally wrong a series of actions were - with one being acceptable and seven being very wrong.
The actions included stealing money from a wallet, lying on a job application, cooking and eating the family dog, killing a dying plane crash survivor to avoid starvation, and abusing a kitten.
All the 4 volunteers put the actions on the 'wrong' side of the scale. But, in results, the group who had washed their hands was less likely to judge the actions as harshly as the group who had not.
In another experiment, a group was asked to read sentences with words such as 'purity' and 'cleanliness' before being posed the same moral dilemmas. Another group was given sentences with neutral words.
Again, the 'clean' group was less likely to judge the unethical behavior as harshly.
"We like to think we arrive at decisions because we deliberate, but incidental things can influence us. This could have implications when voting and when juries make up their minds," the Daily Mail quoted lead researcher Dr Simone Schnall, a psychologist at the University of Plymouth, as saying.