It’s been scientifically proven that people are more likely to find smokers less attractive.

In a study conducted by researchers at the University of Bristol, over 500 participants were presented with the faces of 23 sets of identical twins, plus a male and female prototype.

The two main aims of the study were to determine whether it’s possible to tell if someone’s a smoker based on their facial features, and whether smoking can impact one’s attractiveness.

There are many factors that can affect a person’s appearance, including age, sex and environment.

Therefore, utilising the faces of identical twins in the study provided the researchers with the degree of control they needed to achieve accurate results.

“Because identical twins share nearly all their genetic material, and some aspects of their environment (e.g. parenting, cultural background, education), differences between them can be attributed to non-shared environmental effects, including differences in lifestyle behaviours such as smoking,” the study stated.

Male and female prototypes of the twins’ faces were also used in the experiment, created by averaging the faces of the other twins.

This is because the slightest difference in expression, pose or lighting had the potential to hinder the outcome of the investigation.

The results of the study were overwhelmingly one-sided, with the male and female participants able to correctly identify which of the male and female prototype faces was the smoker 70 per cent of the time.

Both men and women also predominantly chose the non-smoker prototype faces as the more attractive of the two.

The researchers believe that their findings could be instrumental in promoting changes in smoking behaviour, especially among young people.

They wrote: “Young people are particularly sensitive to the potential negative effects smoking has on their attractiveness as they age.

“The findings, particularly those for the prototypes that represent the characteristic facial features of smokers and non-smokers, have the potential to be of utility in developing and improving smoking behaviour change interventions.”

A study published in June this year discovered that the number of people smoking is on the decline.

Only 15.5 per cent of adults aged over 18 in the UK currently smoke, in comparison to 19.9 per cent recorded in 2010.

Earlier this year, Cancer Research UK teamed up with Abbott Mead Vickers BBDO to launch a campaign called the “Breath Test”.

Passersby at a bus stop were invited to “Take a deep breath and blow here”, to aim their breath on a circle on the interactive ad.

As people blew on the circle, writing appeared explaining that smokers were less likely to read past the first line.