In women, thinner lips are thought to reduce their feminine appearance. Those with full lips are considered to be more attractive and appear more youthful. Scientists at Manchester University conducted a study that demonstrated the attraction of full lips.
In the study, men who were shown different images of women spent an average of sevens seconds gazing at the lips of women who wore lipstick and spent significantly lesser time looking at their other features. The appeal of thin lips also significantly increased by 40 percent with the application of lipstick.